Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
DETAILED ACTION
This action is responsive to the application filed on 8/18/2024.
Claims 1-22 are pending in the case. Claims 1, and 12 are independent claims.
This application claims benefit of domestic Priority under 35 U.S.C. 119 (e) from Provisional U.S. Patent Application No. 63578670, filed on 8/25/2023.
Claim Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
3. Claims 1-6, 11-17, and 22 are rejected under 35 U.S.C. §102(a)(1) as being anticipated by Nayebi et al. (US Patent Application Publication No. 20210377095), published on 12/2/2021 (hereinafter Nayebi).
As for independent claim 1, Nayebi discloses a calibration apparatus for calibrating a transceiver comprising:
a loop back circuit (FIG. 4, loopback path 403), coupled between a mixer output port (Fig.4, Mixer 416) of a transmitter (Tx) of the transceiver and a mixer input port (FIG. 4, Mixer 426/428) of a receiver (Rx) of the transceiver, wherein the loop back circuit (Fig.4, loopback path 403) is configured to apply a sequence of different loop gains (sending first and second signals)(the gain and/or phase shift);
(Paragraph [0027] discloses “FIG. 1 illustrates an embodiment of a quadrature transceiver that may be used to implement joint TX and RX IQMM calibration according to this disclosure.”
Paragraph [0005] discloses “A method of compensating for IQ mismatch (IQMM) in a transceiver may include sending first and second signals from a transmit path through a loopback path, using a phase shifter to introduce a phase shift in at least one of the first and second signals, to obtain first and second signals received by a receive path, using the first and second signals received by the receive path to obtain joint estimates of transmit and receive IQMM, at least in part, by estimating the phase shift, and compensating for IQMM using the estimates of IQMM.”
Paragraph [0036] discloses “In some embodiments, the gain and/or phase shift applied by the phase shifter may be estimated as one or more unknowns in the system of equations. This may enable TX and RX IQMM parameters to be estimated without a priori knowledge of the phase shift.”
Fig.1 also highlights the processor 132 interacting with loopback path 104 for phase control. The loopback path 104 may include a phase shifter.)
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(Paragraph [0045] discloses “FIG. 4 illustrates an example embodiment of a quadrature transceiver that may be used to implement joint TX and RX calibration according to this disclosure.”
Loopback path 400 is between TX Path 400, and RX Path coupled with TX mixer at 412/414 and RX mixer at 426/428, respectively.)
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an estimation circuit (FIG. 1, Compensator 126), configured to receive a loop back receiving signal that is output from the Rx under the sequence (first and second signals) of different loop gains (FIG.1, phase shifter 104)(the gain and/or phase shift), and generate at least one estimated value (joint estimates) of impairment of the transceiver (IQ Mismatch) by performing channel estimation according to at least the loop back receiving signal (receive path); and
(Paragraph [0005] discloses “A method of compensating for IQ mismatch (IQMM) in a transceiver may include sending first and second signals from a transmit path through a loopback path, using a phase shifter to introduce a phase shift in at least one of the first and second signals, to obtain first and second signals received by a receive path, using the first and second signals received by the receive path to obtain joint estimates of transmit and receive IQMM, at least in part, by estimating the phase shift, and compensating for IQMM using the estimates of IQMM.”
Paragraph [0036] discloses “In some embodiments, the gain and/or phase shift applied by the phase shifter may be estimated as one or more unknowns in the system of equations. This may enable TX and RX IQMM parameters to be estimated without a priori knowledge of the phase shift”
Nayebi Fig.1 discloses the compensator.)
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a calibration circuit (FIG. 1), arranged to perform calibration upon the transceiver (estimating the phase shift, and compensating for IQMM using the estimates of IQMM) according to the at least one estimated value.
(Paragraph [0005] discloses “A method of compensating for IQ mismatch (IQMM) in a transceiver may include sending first and second signals from a transmit path through a loopback path, using a phase shifter to introduce a phase shift in at least one of the first and second signals, to obtain first and second signals received by a receive path, using the first and second signals received by the receive path to obtain joint estimates of transmit and receive IQMM, at least in part, by estimating the phase shift, and compensating for IQMM using the estimates of IQMM.”
Paragraph [0009] discloses “FIG. 1 illustrates an embodiment of a quadrature transceiver that may be used to implement joint TX and RX IQMM calibration according to this disclosure.”
Please refer to FIG. 1 above, the processing unit interface to the Pre-Compensator 108 and Compensator 126 to perform joint TX and RX IQMM calibration.)
As for claim 2, Nayebi discloses the calibration apparatus of claim 1,
wherein the loop back circuit comprises: a phase shifter (loopback path 104 may include a phase shifter), configured to apply the sequence of different loop gains (sending first and second)(the gain and/or phase shift) by performing a multi-phase phase rotation (first, second, and third signals).
(Paragraph [0028] discloses “The loopback path 104 may be coupled between the TX path 100 and the RX path 102. The loopback path 104 may include a phase shifter, but in various embodiments, the phase shifter may alternatively be located in the TX path 100, in the RX path 102, or may have functionality distributed between multiple paths and/or components.”
Paragraph [0005] discloses “A method of compensating for IQ mismatch (IQMM) in a transceiver may include sending first and second signals from a transmit path through a loopback path, using a phase shifter to introduce a phase shift in at least one of the first and second signals, to obtain first and second signals received by a receive path, using the first and second signals received by the receive path to obtain joint estimates of transmit and receive IQMM, at least in part, by estimating the phase shift, and compensating for IQMM using the estimates of IQMM. The method may further include sending a third signal from the transmit path through the loopback path, using the phase shifter to introduce a phase shift in at least two of the first, second, and third signals, to obtain a third signal received by the receive path, and using the first, second, and third signals received by the receive path to obtain joint estimates of the transmit and receive IQMM, at least in part, by estimating the phase shift. Using the first and second signals received by the receive path to obtain estimates of the IQMM may include processing the first and second signals received by the receive path as a function of one or more frequency-dependent IQMM parameters.”
Paragraph [0036] discloses “In some embodiments, the gain and/or phase shift applied by the phase shifter may be estimated as one or more unknowns in the system of equations. This may enable TX and RX IQMM parameters to be estimated without a priori knowledge of the phase shift”
FIG. 1 highlights the processor 132 interacting with loopback path 104 for phase control. The loopback path 104 may include a phase shifter. Broadest reasonable interpretation of phase rotation is a sequence of signals (e.g. the first, second, and third signals) use for calibration of the transceiver.)
As for claim 3, Nayebi discloses the calibration apparatus of claim 1,
wherein the channel estimation (jointly estimating IQMM) performed by the estimation circuit comprises:
receiving (RX path through a loopback path) a baseband input of the Tx of the transceiver (baseband to the TX path); and
(Paragraph [0021] discloses “This disclosure encompasses numerous inventive principles relating to in-phase (I) and quadrature (Q) mismatch (IQMM) in quadrature transceivers. Some of the principles involve techniques for jointly estimating IQMM, which may include frequency-dependent IQMM (FD-IQMM), in both the transmit (TX) and receive (RX) paths of a quadrature transceiver. In some embodiments, two or more pilot signals may be applied at baseband to the TX path which may be coupled to the RX path through a loopback path. Different phase shifts may be applied to the pilot signals, for example, through the use of a phase shifter in the loopback path. The received pilot signals may be observed at baseband of the RX path and analyzed using various disclosed algorithms to estimate the IQMM in both the TX and RX paths.”)
Estimating (estimate the IQMM) a plurality of Tx-to-Rx loop channel (two or more pilot signals) responses of signal by performing delay correlation (may account for a gain and/or delay associated with transmission and/or receiver links) to project the loop back receiving signal onto the baseband input of the Tx of the transceiver (pilot signals may be applied at baseband to the TX path which may be coupled to the RX path through a loopback path), where the plurality of Tx-to-Rx loop channel responses of signal correspond to the different loop gains (the gain and/or phase shift), respectively.
(Paragraph [0021] discloses “This disclosure encompasses numerous inventive principles relating to in-phase (I) and quadrature (Q) mismatch (IQMM) in quadrature transceivers. Some of the principles involve techniques for jointly estimating IQMM, which may include frequency-dependent IQMM (FD-IQMM), in both the transmit (TX) and receive (RX) paths of a quadrature transceiver. In some embodiments, two or more pilot signals may be applied at baseband to the TX path which may be coupled to the RX path through a loopback path. Different phase shifts may be applied to the pilot signals, for example, through the use of a phase shifter in the loopback path. The received pilot signals may be observed at baseband of the RX path and analyzed using various disclosed algorithms to estimate the IQMM in both the TX and RX paths.”
Paragraph [0024] discloses “In various embodiments, one or more of the IQMM parameters may be related to physical aspects of a transceiver such as the frequency response of a filter, a scaling factor that may account for a gain and/or delay associated with transmission and/or receiver links, the gain and/or phase mismatch of mixers, and/or the like. In some embodiments, one or more unknown variables may account for a phase shift applied to a pilot signal. This may enable IQ mismatch to be estimated without knowing one or more values of the phase shift, for example, by estimating or solving for the phase shift.”
Paragraph [0036] discloses “In some embodiments, the gain and/or phase shift applied by the phase shifter may be estimated as one or more unknowns in the system of equations. This may enable TX and RX IQMM parameters to be estimated without a priori knowledge of the phase shift”)
As for claim 4, Nayebi discloses the calibration apparatus of claim 3,
wherein the channel estimation performed by the estimation circuit further comprises:
referring to the plurality of Tx-to-Rx loop channel responses of signal(first pilot signal at a first frequency, a second pilot signal at a second frequency) to extract the different loop gains (the gain and phase mismatches at the RX mixers) and an equivalent baseband channel response of a Tx-to-Rx (first, second, and third pilot signal at a first, second, and third frequency) coupling total interference signal (creating interference between the mirror frequencies after down-conversion).
(Paragraph [0007] discloses “The re-estimate of the RX phase mismatch may be a first re-estimate for a first pilot signal at a first frequency, and the method may further include obtaining a second re-estimate of the RX phase mismatch for a second pilot signal at a second frequency, and correcting the initial value of the cross-multiplication factor based on the first and second re-estimate of the RX phase mismatch. The method may further include obtaining a third re-estimate of the RX phase mismatch for a third pilot signal at a third frequency, and correcting the initial value of the cross-multiplication factor based on the first, second, and third re-estimate of the RX phase mismatch.”
Paragraph [0029] discloses “The TX path 100 and the RX path 102 may each include an I path and a Q path. Imbalances or mismatches between the I and Q paths (IQMM) may degrade system performance, for example, by creating interference between the mirror frequencies after down-conversion to baseband in the RX path 102 and/or after up-conversion to radio frequency (RF) or intermediate frequency (IF) in the TX path 100.”
Paragraph [0048] discloses “In the RX path 402, the gain and phase mismatches at the RX mixers 426 and 428 may be donated by g.sub.RX≠1 and ϕ.sub.RX≠0, respectively, and may create the FI-IQMM at the down-converter. The FD-IQMM on RX path may be caused by mismatch between the impulse responses of h.sub.1RX(t) and h.sub.2RX(t).”)
As for claim 5, Nayebi discloses the calibration apparatus of claim 1,
wherein the channel estimation performed by the estimation circuit comprises:
receiving a baseband input of the Tx of the transceiver (baseband equivalent of the upconverted signal in the TX path); and
(Paragraph [0049] discloses “The baseband equivalent of the upconverted signal in the TX path 400 (at the output of mixers) in frequency-domain may be given by Z.sub.TX(f)=G.sub.1TX(f)U(f)+G.sub.2TX(f)U*(−f), (1).”)
estimating a plurality (two or more pilot signals) of Tx-to-Rx loop channel responses of image (represent a TX image signal) by performing delay correlation (for a gain and/or delay associated with transmission and/or receiver links) to project (jointly estimating IQMM) the loop back (loopback path) receiving signal onto an image of the baseband input of the Tx of the transceiver (represent a TX image signal), where the plurality of Tx-to-Rx loop channel responses of image correspond to the different loop gains (Different phase shifts may be applied to the pilot signals)(the gain and/or phase shift), respectively.
(Paragraph [0021] discloses “This disclosure encompasses numerous inventive principles relating to in-phase (I) and quadrature (Q) mismatch (IQMM) in quadrature transceivers. Some of the principles involve techniques for jointly estimating IQMM, which may include frequency-dependent IQMM (FD-IQMM), in both the transmit (TX) and receive (RX) paths of a quadrature transceiver. In some embodiments, two or more pilot signals may be applied at baseband to the TX path which may be coupled to the RX path through a loopback path. Different phase shifts may be applied to the pilot signals, for example, through the use of a phase shifter in the loopback path. The received pilot signals may be observed at baseband of the RX path and analyzed using various disclosed algorithms to estimate the IQMM in both the TX and RX paths.”
Paragraph [0024] discloses “In various embodiments, one or more of the IQMM parameters may be related to physical aspects of a transceiver such as the frequency response of a filter, a scaling factor that may account for a gain and/or delay associated with transmission and/or receiver links, the gain and/or phase mismatch of mixers, and/or the like. In some embodiments, one or more unknown variables may account for a phase shift applied to a pilot signal. This may enable IQ mismatch to be estimated without knowing one or more values of the phase shift, for example, by estimating or solving for the phase shift.”
Paragraph [0036] discloses “In some embodiments, the gain and/or phase shift applied by the phase shifter may be estimated as one or more unknowns in the system of equations. This may enable TX and RX IQMM parameters to be estimated without a priori knowledge of the phase shift”
Paragraph [0050] discloses “In Equations (2), H.sub.1TX(f) and H.sub.2TX(f) may denote the frequency responses of filter 408 (h.sub.1TX(t)) and filter 410 (h.sub.2TX(t)), respectively. In Equation (1), G.sub.1TX(f)U(f) may represent a desired TX signal, and G.sub.2TX(f)U*(−f) may represent a TX image signal. Without any IQMM, (g.sub.TX=1, ϕ.sub.TX=0, and h.sub.1TX(t)=h.sub.2TX(t)), G.sub.2TX(f), and consequently, the second term in Equation (1) may become zero.”
Paragraph [0051] discloses “The effect of IQMM at the output of low-pass filters in the RX path 402 may be expressed as the addition of a filtered mirror image of the principal frequency and the ideal signal as follows”
FIG. 4 shows up-conversion and down-conversion, where the mixers (412, 414, 426, 428) and filters (408, 410, 430, 432) introduce gain and/or delay within the calibration circuit (pre-compensator/DAC/up-conversion/phase-shifter/down-conversion/ADC/compensator). In a closed loop circuit, the processor uses the delay to compensate for the transmit signal at the compensator, thus, the delay correlation to determine IQMM mismatch.)
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As for claim 6, Nayebi discloses the calibration apparatus of claim 5,
wherein the channel estimation performed by the estimation circuit further comprises:
referring to the plurality of Tx-to-Rx loop channel (the TX path, a loopback path/phase shifter, RX path) responses of image to extract at least two (two or more pilot signals may be applied at baseband to the TX path)( received pilot signals may be observed at baseband of the RX path) of an equivalent baseband Tx total image channel (represent a TX image signal) response, an equivalent baseband Rx total image channel response (mirror image of the principal frequency and the ideal signal), and an equivalent baseband channel response of a Tx-to-Rx coupling total interference image (interfering image signal).
(Paragraph [0021] discloses “This disclosure encompasses numerous inventive principles relating to in-phase (I) and quadrature (Q) mismatch (IQMM) in quadrature transceivers. Some of the principles involve techniques for jointly estimating IQMM, which may include frequency-dependent IQMM (FD-IQMM), in both the transmit (TX) and receive (RX) paths of a quadrature transceiver. In some embodiments, two or more pilot signals may be applied at baseband to the TX path which may be coupled to the RX path through a loopback path. Different phase shifts may be applied to the pilot signals, for example, through the use of a phase shifter in the loopback path. The received pilot signals may be observed at baseband of the RX path and analyzed using various disclosed algorithms to estimate the IQMM in both the TX and RX paths.”
Paragraph [0050] discloses “In Equations (2), H.sub.1TX(f) and H.sub.2TX(f) may denote the frequency responses of filter 408 (h.sub.1TX(t)) and filter 410 (h.sub.2TX(t)), respectively. In Equation (1), G.sub.1TX(f)U(f) may represent a desired TX signal, and G.sub.2TX(f)U*(−f) may represent a TX image signal. Without any IQMM, (g.sub.TX=1, ϕ.sub.TX=0, and h.sub.1TX(t)=h.sub.2TX(t)), G.sub.2TX(f), and consequently, the second term in Equation (1) may become zero.”
Paragraph [0051] discloses “The effect of IQMM at the output of low-pass filters in the RX path 402 may be expressed as the addition of a filtered mirror image of the principal frequency and the ideal signal as follows”
Paragraph [0052] discloses “In Equations (4), H.sub.1RX(f) and H.sub.2RX(f) may denote the frequency responses of filter 430 (h.sub.1RX(t)) and filter 432 (h.sub.2RX(t)), respectively. In Equation (3), G.sub.1RX(f)Z.sub.RX(f) may represent a desired RX signal, and G.sub.2RX(f)Z.sub.RX*(−f) may represent interfering image signal due to RX IQMM.”)
As for claim 11, The calibration apparatus of claim 1,
wherein the calibration is static calibration, and the loop back receiving signal (a loopback path) is generated in response to a baseband input of the Tx of the transceiver (baseband to the TX path) that is a non-modulation signal (pilot signal).
(Paragraph [0021] discloses “This disclosure encompasses numerous inventive principles relating to in-phase (I) and quadrature (Q) mismatch (IQMM) in quadrature transceivers. Some of the principles involve techniques for jointly estimating IQMM, which may include frequency-dependent IQMM (FD-IQMM), in both the transmit (TX) and receive (RX) paths of a quadrature transceiver. In some embodiments, two or more pilot signals may be applied at baseband to the TX path which may be coupled to the RX path through a loopback path. Different phase shifts may be applied to the pilot signals, for example, through the use of a phase shifter in the loopback path. The received pilot signals may be observed at baseband of the RX path and analyzed using various disclosed algorithms to estimate the IQMM in both the TX and RX paths.”
Paragraph [0032] discloses “To determine values of IQMM parameters, one or more pilot signals (e.g., single-tone or multi-tone signals) may be sent through a pilot signal path which may include the TX path 100, the loopback path 104, and the RX path 102. The pilot signal received at the RX path 102 may have TX-IQMM and RX-IQMM parameters entangled with each other.”
Current invention discloses calibration on-the-fly (OTF) also known as background calibration. The baseband input is a non-modulation signal (e.g., a pseudo random code (PNC) signal, a single-tone signal, or a multi-tone signal) that is specific to the calibration task and carries no valid user data. The claim indicates a non-modulation signal. Broadest reasonable interpretation for static calibration to be a control testing with a single-tone pilot signal.)
As for claim 12, Nayebi discloses a calibration method for calibrating a transceiver comprising:
controlling a loop back circuit (FIG. 4, loopback path 403) to apply a sequence of different loop gains (sending first and second signals)(the gain and/or phase shift), wherein the loop back circuit is coupled between a mixer output port (Fig.4, Mixer 416) of a transmitter (Tx) of the transceiver and a mixer input port (FIG. 4, Mixer 426/428) of a receiver (Rx) of the transceiver;
(Paragraph [0027] discloses “FIG. 1 illustrates an embodiment of a quadrature transceiver that may be used to implement joint TX and RX IQMM calibration according to this disclosure.”
Paragraph [0005] discloses “A method of compensating for IQ mismatch (IQMM) in a transceiver may include sending first and second signals from a transmit path through a loopback path, using a phase shifter to introduce a phase shift in at least one of the first and second signals, to obtain first and second signals received by a receive path, using the first and second signals received by the receive path to obtain joint estimates of transmit and receive IQMM, at least in part, by estimating the phase shift, and compensating for IQMM using the estimates of IQMM.”
Paragraph [0036] discloses “In some embodiments, the gain and/or phase shift applied by the phase shifter may be estimated as one or more unknowns in the system of equations. This may enable TX and RX IQMM parameters to be estimated without a priori knowledge of the phase shift.”
Fig.1 also highlights the processor 132 interacting with loopback path 104 for phase control. The loopback path 104 may include a phase shifter.)
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(Paragraph [0045] discloses “FIG. 4 illustrates an example embodiment of a quadrature transceiver that may be used to implement joint TX and RX calibration according to this disclosure.”
Loopback path 400 is between TX Path 400, and RX Path coupled with TX mixer at 412/414 and RX mixer at 426/428, respectively.)
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receiving a loop back receiving signal from the Rx (the first and second signals received by the receive path) under the sequence of different loop gains (sending first and second signals)(the gain and/or phase shift);
(Paragraph [0027] discloses “FIG. 1 illustrates an embodiment of a quadrature transceiver that may be used to implement joint TX and RX IQMM calibration according to this disclosure.”
Paragraph [0005] discloses “A method of compensating for IQ mismatch (IQMM) in a transceiver may include sending first and second signals from a transmit path through a loopback path, using a phase shifter to introduce a phase shift in at least one of the first and second signals, to obtain first and second signals received by a receive path, using the first and second signals received by the receive path to obtain joint estimates of transmit and receive IQMM, at least in part, by estimating the phase shift, and compensating for IQMM using the estimates of IQMM.”
Paragraph [0036] discloses “In some embodiments, the gain and/or phase shift applied by the phase shifter may be estimated as one or more unknowns in the system of equations. This may enable TX and RX IQMM parameters to be estimated without a priori knowledge of the phase shift.”)
generating at least one estimated value (joint estimates) of impairment of the transceiver (IQ Mismatch) by performing channel estimation according to at least the loop back receiving signal (first and second signals)( the gain and/or phase shift);
(Paragraph [0005] discloses “A method of compensating for IQ mismatch (IQMM) in a transceiver may include sending first and second signals from a transmit path through a loopback path, using a phase shifter to introduce a phase shift in at least one of the first and second signals, to obtain first and second signals received by a receive path, using the first and second signals received by the receive path to obtain joint estimates of transmit and receive IQMM, at least in part, by estimating the phase shift, and compensating for IQMM using the estimates of IQMM.”
Paragraph [0036] discloses “In some embodiments, the gain and/or phase shift applied by the phase shifter may be estimated as one or more unknowns in the system of equations. This may enable TX and RX IQMM parameters to be estimated without a priori knowledge of the phase shift”
Nayebi Fig.1 discloses the compensator.)
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and performing calibration upon the transceiver according to the at least one estimated value (estimating the phase shift, and compensating for IQMM using the estimates of IQMM).
(Paragraph [0005] discloses “A method of compensating for IQ mismatch (IQMM) in a transceiver may include sending first and second signals from a transmit path through a loopback path, using a phase shifter to introduce a phase shift in at least one of the first and second signals, to obtain first and second signals received by a receive path, using the first and second signals received by the receive path to obtain joint estimates of transmit and receive IQMM, at least in part, by estimating the phase shift, and compensating for IQMM using the estimates of IQMM.”
Paragraph [0009] discloses “FIG. 1 illustrates an embodiment of a quadrature transceiver that may be used to implement joint TX and RX IQMM calibration according to this disclosure.”
Please refer to FIG. 1 above, the processing unit interface to the Pre-Compensator 108 and Compensator 126 to perform joint TX and RX IQMM calibration.)
As for claim 13, Nayebi discloses the calibration method of claim 12,
wherein the loop back circuit comprises a phase shifter (loopback path 104 may include a phase shifter), and controlling the loop back circuit to apply the sequence of different loop gains (sending first and second)(the gain and/or phase shift) comprises: applying the sequence of different loop gains by controlling the phase shifter (sending first and second)(the gain and/or phase shift) to perform a multi-phase phase rotation (first, second, and third signals).
(Paragraph [0028] discloses “The loopback path 104 may be coupled between the TX path 100 and the RX path 102. The loopback path 104 may include a phase shifter, but in various embodiments, the phase shifter may alternatively be located in the TX path 100, in the RX path 102, or may have functionality distributed between multiple paths and/or components.”
Paragraph [0005] discloses “A method of compensating for IQ mismatch (IQMM) in a transceiver may include sending first and second signals from a transmit path through a loopback path, using a phase shifter to introduce a phase shift in at least one of the first and second signals, to obtain first and second signals received by a receive path, using the first and second signals received by the receive path to obtain joint estimates of transmit and receive IQMM, at least in part, by estimating the phase shift, and compensating for IQMM using the estimates of IQMM. The method may further include sending a third signal from the transmit path through the loopback path, using the phase shifter to introduce a phase shift in at least two of the first, second, and third signals, to obtain a third signal received by the receive path, and using the first, second, and third signals received by the receive path to obtain joint estimates of the transmit and receive IQMM, at least in part, by estimating the phase shift. Using the first and second signals received by the receive path to obtain estimates of the IQMM may include processing the first and second signals received by the receive path as a function of one or more frequency-dependent IQMM parameters.”
Paragraph [0036] discloses “In some embodiments, the gain and/or phase shift applied by the phase shifter may be estimated as one or more unknowns in the system of equations. This may enable TX and RX IQMM parameters to be estimated without a priori knowledge of the phase shift”
FIG. 1 highlights the processor 132 interacting with loopback path 104 for phase control. The loopback path 104 may include a phase shifter. Broadest reasonable interpretation of phase rotation is a sequence of signals (e.g. the first, second, and third signals) use for calibration of the transceiver.)
As for claim 14, Nayebi discloses the calibration method of claim 12,
wherein the channel estimation (jointly estimating IQMM) performed by the estimation circuit comprises: receiving (RX path through a loopback path) a baseband input of the Tx of the transceiver (baseband to the TX path);
(Paragraph [0021] discloses “This disclosure encompasses numerous inventive principles relating to in-phase (I) and quadrature (Q) mismatch (IQMM) in quadrature transceivers. Some of the principles involve techniques for jointly estimating IQMM, which may include frequency-dependent IQMM (FD-IQMM), in both the transmit (TX) and receive (RX) paths of a quadrature transceiver. In some embodiments, two or more pilot signals may be applied at baseband to the TX path which may be coupled to the RX path through a loopback path. Different phase shifts may be applied to the pilot signals, for example, through the use of a phase shifter in the loopback path. The received pilot signals may be observed at baseband of the RX path and analyzed using various disclosed algorithms to estimate the IQMM in both the TX and RX paths.”)
and estimating (estimate the IQMM) a plurality of Tx-to-Rx loop channel responses of signal (two or more pilot signals) by performing delay correlation (may account for a gain and/or delay associated with transmission and/or receiver links) to project the loop back receiving signal onto the baseband input of the Tx of the transceiver (pilot signals may be applied at baseband to the TX path which may be coupled to the RX path through a loopback path), where the plurality of Tx-to-Rx loop channel responses of signal correspond to the different loop gains (the gain and/or phase shift), respectively.
(Paragraph [0021] discloses “This disclosure encompasses numerous inventive principles relating to in-phase (I) and quadrature (Q) mismatch (IQMM) in quadrature transceivers. Some of the principles involve techniques for jointly estimating IQMM, which may include frequency-dependent IQMM (FD-IQMM), in both the transmit (TX) and receive (RX) paths of a quadrature transceiver. In some embodiments, two or more pilot signals may be applied at baseband to the TX path which may be coupled to the RX path through a loopback path. Different phase shifts may be applied to the pilot signals, for example, through the use of a phase shifter in the loopback path. The received pilot signals may be observed at baseband of the RX path and analyzed using various disclosed algorithms to estimate the IQMM in both the TX and RX paths.”
Paragraph [0024] discloses “In various embodiments, one or more of the IQMM parameters may be related to physical aspects of a transceiver such as the frequency response of a filter, a scaling factor that may account for a gain and/or delay associated with transmission and/or receiver links, the gain and/or phase mismatch of mixers, and/or the like. In some embodiments, one or more unknown variables may account for a phase shift applied to a pilot signal. This may enable IQ mismatch to be estimated without knowing one or more values of the phase shift, for example, by estimating or solving for the phase shift.”
Paragraph [0036] discloses “In some embodiments, the gain and/or phase shift applied by the phase shifter may be estimated as one or more unknowns in the system of equations. This may enable TX and RX IQMM parameters to be estimated without a priori knowledge of the phase shift”)
As for claim 15, Nayebi discloses the calibration method of claim 14,
wherein performing the channel estimation according to at least the loop back receiving signal further comprises: referring to the plurality of Tx-to-Rx loop channel responses of signal (first pilot signal at a first frequency, a second pilot signal at a second frequency) to extract the different loop gains (the gain and phase mismatches at the RX mixers) and an equivalent baseband channel response of a Tx-to-Rx (first, second, and third pilot signal at a first, second, and third frequency) coupling total interference signal (creating interference between the mirror frequencies after down-conversion).
(Paragraph [0007] discloses “The re-estimate of the RX phase mismatch may be a first re-estimate for a first pilot signal at a first frequency, and the method may further include obtaining a second re-estimate of the RX phase mismatch for a second pilot signal at a second frequency, and correcting the initial value of the cross-multiplication factor based on the first and second re-estimate of the RX phase mismatch. The method may further include obtaining a third re-estimate of the RX phase mismatch for a third pilot signal at a third frequency, and correcting the initial value of the cross-multiplication factor based on the first, second, and third re-estimate of the RX phase mismatch.”
Paragraph [0029] discloses “The TX path 100 and the RX path 102 may each include an I path and a Q path. Imbalances or mismatches between the I and Q paths (IQMM) may degrade system performance, for example, by creating interference between the mirror frequencies after down-conversion to baseband in the RX path 102 and/or after up-conversion to radio frequency (RF) or intermediate frequency (IF) in the TX path 100.”
Paragraph [0048] discloses “In the RX path 402, the gain and phase mismatches at the RX mixers 426 and 428 may be donated by g.sub.RX≠1 and ϕ.sub.RX≠0, respectively, and may create the FI-IQMM at the down-converter. The FD-IQMM on RX path may be caused by mismatch between the impulse responses of h.sub.1RX(t) and h.sub.2RX(t).”)
As for claim 16, The calibration method of claim 12,
wherein performing the channel estimation according to at least the loop back receiving signal comprises: receiving a baseband input of the Tx of the transceiver (baseband equivalent of the upconverted signal in the TX path); and
(Paragraph [0049] discloses “The baseband equivalent of the upconverted signal in the TX path 400 (at the output of mixers) in frequency-domain may be given by Z.sub.TX(f)=G.sub.1TX(f)U(f)+G.sub.2TX(f)U*(−f), (1).”)
estimating a plurality (two or more pilot signals) of Tx-to-Rx loop channel responses of image represent a TX image signal) by performing delay correlation (for a gain and/or delay associated with transmission and/or receiver links) to project (jointly estimating IQMM) the loop back (loopback path) receiving signal onto an image of the baseband input of the Tx of the transceiver (represent a TX image signal), where the plurality of Tx-to-Rx loop channel responses of image correspond to the different loop gains (Different phase shifts may be applied to the pilot signals)(the gain and/or phase shift), respectively.
(Paragraph [0021] discloses “This disclosure encompasses numerous inventive principles relating to in-phase (I) and quadrature (Q) mismatch (IQMM) in quadrature transceivers. Some of the principles involve techniques for jointly estimating IQMM, which may include frequency-dependent IQMM (FD-IQMM), in both the transmit (TX) and receive (RX) paths of a quadrature transceiver. In some embodiments, two or more pilot signals may be applied at baseband to the TX path which may be coupled to the RX path through a loopback path. Different phase shifts may be applied to the pilot signals, for example, through the use of a phase shifter in the loopback path. The received pilot signals may be observed at baseband of the RX path and analyzed using various disclosed algorithms to estimate the IQMM in both the TX and RX paths.”
Paragraph [0024] discloses “In various embodiments, one or more of the IQMM parameters may be related to physical aspects of a transceiver such as the frequency response of a filter, a scaling factor that may account for a gain and/or delay associated with transmission and/or receiver links, the gain and/or phase mismatch of mixers, and/or the like. In some embodiments, one or more unknown variables may account for a phase shift applied to a pilot signal. This may enable IQ mismatch to be estimated without knowing one or more values of the phase shift, for example, by estimating or solving for the phase shift.”
Paragraph [0036] discloses “In some embodiments, the gain and/or phase shift applied by the phase shifter may be estimated as one or more unknowns in the system of equations. This may enable TX and RX IQMM parameters to be estimated without a priori knowledge of the phase shift”
Paragraph [0050] discloses “In Equations (2), H.sub.1TX(f) and H.sub.2TX(f) may denote the frequency responses of filter 408 (h.sub.1TX(t)) and filter 410 (h.sub.2TX(t)), respectively. In Equation (1), G.sub.1TX(f)U(f) may represent a desired TX signal, and G.sub.2TX(f)U*(−f) may represent a TX image signal. Without any IQMM, (g.sub.TX=1, ϕ.sub.TX=0, and h.sub.1TX(t)=h.sub.2TX(t)), G.sub.2TX(f), and consequently, the second term in Equation (1) may become zero.”
Paragraph [0051] discloses “The effect of IQMM at the output of low-pass filters in the RX path 402 may be expressed as the addition of a filtered mirror image of the principal frequency and the ideal signal as follows”
FIG. 4 shows up-conversion and down-conversion, where the mixers (412, 414, 426, 428) and filters (408, 410, 430, 432) introduce gain and/or delay within the calibration circuit (pre-compensator/DAC/up-conversion/phase-shifter/down-conversion/ADC/compensator). In a closed loop circuit, the processor uses the delay to compensate for the transmit signal at the compensator, thus, the delay correlation to determine IQMM mismatch.)
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As for claim 17, Nayebi discloses the calibration method of claim 16,
wherein performing the channel estimation according to at least the loop back receiving signal further comprises: referring to the plurality of Tx-to-Rx loop channel (the TX path, a loopback path/phase shifter, RX path) responses of image to extract at least two (two or more pilot signals may be applied at baseband to the TX path)( received pilot signals may be observed at baseband of the RX path) of an equivalent baseband Tx total image channel (represent a TX image signal) response, an equivalent baseband Rx total image channel response (mirror image of the principal frequency and the ideal signal), and an equivalent baseband channel response of a Tx-to-Rx coupling total interference image (interfering image signal).
(Paragraph [0021] discloses “This disclosure encompasses numerous inventive principles relating to in-phase (I) and quadrature (Q) mismatch (IQMM) in quadrature transceivers. Some of the principles involve techniques for jointly estimating IQMM, which may include frequency-dependent IQMM (FD-IQMM), in both the transmit (TX) and receive (RX) paths of a quadrature transceiver. In some embodiments, two or more pilot signals may be applied at baseband to the TX path which may be coupled to the RX path through a loopback path. Different phase shifts may be applied to the pilot signals, for example, through the use of a phase shifter in the loopback path. The received pilot signals may be observed at baseband of the RX path and analyzed using various disclosed algorithms to estimate the IQMM in both the TX and RX paths.”
Paragraph [0050] discloses “In Equations (2), H.sub.1TX(f) and H.sub.2TX(f) may denote the frequency responses of filter 408 (h.sub.1TX(t)) and filter 410 (h.sub.2TX(t)), respectively. In Equation (1), G.sub.1TX(f)U(f) may represent a desired TX signal, and G.sub.2TX(f)U*(−f) may represent a TX image signal. Without any IQMM, (g.sub.TX=1, ϕ.sub.TX=0, and h.sub.1TX(t)=h.sub.2TX(t)), G.sub.2TX(f), and consequently, the second term in Equation (1) may become zero.”
Paragraph [0051] discloses “The effect of IQMM at the output of low-pass filters in the RX path 402 may be expressed as the addition of a filtered mirror image of the principal frequency and the ideal signal as follows”
Paragraph [0052] discloses “In Equations (4), H.sub.1RX(f) and H.sub.2RX(f) may denote the frequency responses of filter 430 (h.sub.1RX(t)) and filter 432 (h.sub.2RX(t)), respectively. In Equation (3), G.sub.1RX(f)Z.sub.RX(f) may represent a desired RX signal, and G.sub.2RX(f)Z.sub.RX*(−f) may represent interfering image signal due to RX IQMM.”)
As for claim 22, Nayebi discloses the calibration method of claim 12,
wherein the calibration is static calibration (single-tone), and the loop back receiving signal (a loopback path) is generated in response to a baseband input of the Tx of the transceiver (baseband to the TX path) that is a non-modulation signal (pilot signal).
(Paragraph [0021] discloses “This disclosure encompasses numerous inventive principles relating to in-phase (I) and quadrature (Q) mismatch (IQMM) in quadrature transceivers. Some of the principles involve techniques for jointly estimating IQMM, which may include frequency-dependent IQMM (FD-IQMM), in both the transmit (TX) and receive (RX) paths of a quadrature transceiver. In some embodiments, two or more pilot signals may be applied at baseband to the TX path which may be coupled to the RX path through a loopback path. Different phase shifts may be applied to the pilot signals, for example, through the use of a phase shifter in the loopback path. The received pilot signals may be observed at baseband of the RX path and analyzed using various disclosed algorithms to estimate the IQMM in both the TX and RX paths.”
Paragraph [0032] discloses “To determine values of IQMM parameters, one or more pilot signals (e.g., single-tone or multi-tone signals) may be sent through a pilot signal path which may include the TX path 100, the loopback path 104, and the RX path 102. The pilot signal received at the RX path 102 may have TX-IQMM and RX-IQMM parameters entangled with each other.”
Current invention discloses calibration on-the-fly (OTF) also known as background calibration. The baseband input is a non-modulation signal (e.g., a pseudo random code (PNC) signal, a single-tone signal, or a multi-tone signal) that is specific to the calibration task and carries no valid user data. The claim indicates a non-modulation signal. Broadest reasonable interpretation for static calibration to be a control testing with a single-tone pilot signal.)
Claim Rejections - 35 USC § 103
5. In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
6. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
7. The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
8. Claims 7-9, and 18-20 are rejected under 35 U.S.C. 103 as being unpatentable over Nayebi as applied to in view of Liu et al., US Patent No. 10116485, filed on 10/31/2017 (hereinafter Liu).
As for claim 7, The calibration apparatus of claim 1,
wherein the channel estimation performed by the estimation circuit comprises:
estimating a plurality (two or more pilot signals) of Tx-to-Rx loop (the TX path, loopback path/ phase shifter, the RX path) (the gain and/or phase shift), respectively.
(Paragraph [0021] discloses “This disclosure encompasses numerous inventive principles relating to in-phase (I) and quadrature (Q) mismatch (IQMM) in quadrature transceivers. Some of the principles involve techniques for jointly estimating IQMM, which may include frequency-dependent IQMM (FD-IQMM), in both the transmit (TX) and receive (RX) paths of a quadrature transceiver. In some embodiments, two or more pilot signals may be applied at baseband to the TX path which may be coupled to the RX path through a loopback path. Different phase shifts may be applied to the pilot signals, for example, through the use of a phase shifter in the loopback path. The received pilot signals may be observed at baseband of the RX path and analyzed using various disclosed algorithms to estimate the IQMM in both the TX and RX paths.”)
Nayebi does not appear to explicitly disclose total direct current (DC) values by averaging the loop back receiving signal. However, Liu discloses total direct current (DC) values (DC terms) by averaging the loop back receiving signal (The third frequency-domain output signal may be expressed as a function of the first and second frequency-domain output signals).
In a similar field of endeavor, (Liu discloses “In the first step, the training signal is transmitted through the calibration path of the transceiver (such as through the transceiver's calibration path) at a tone k with the phase shifter 432 operating in the bypass state, for example, where S.sub.k=1 and S.sub. −k=0. Using the above-derived frequency-domain representations of the training signal, it may be shown that Y.sub.k(ϕ.sub.0) ≅C.sub.k (ϕ.sub.0) and that:
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where ϕ.sub.0 is the phase of the phase shifter 432 when operating in the bypass state. The DC terms may be expressed as:
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The channel response at DC may be approximated by measuring a tone m near the DC tone, where the value of m may be an integer (such as 1 or 2). Because C.sub.0(ϕ.sub.0)≅Y.sub.m(ϕ.sub.0), the DC terms may be rewritten, without the phase shift introduced by the phase shifter 432, as:
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[Col. 16, Line 25-44]”
Liu discloses “Although the DC tone values of the first frequency-domain output signal {Y.sub.k.sup.P(ϕ.sub.0)} and the second frequency-domain output signal {Y.sub.k.sup.N(ϕ.sub.0)} may differ because of the insertion of the first and second known TXCL correction values +Δ and −Δ into the first and second FDMT waveforms, respectively, other tone values of the first and second frequency-domain output signals remain constant (excluding variation in noise). The third frequency-domain output signal may be expressed as a function of the first and second frequency-domain output signals, for example, using the expression
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The resulting value {Y.sub.k(ϕ.sub.0)} may be combined with the value {Y.sub.k(ϕ.sub.1)} to estimate the transmitter I/Q imbalance and the receiver I/Q imbalance contemporaneously. [Col. 22, Line 43-62]”
Liu defined the expression to determine DC value(s) with/without a phase shifter for each signal traverse the loopback path. Liu further discloses the resulting DC values for signal N and P can result in an average DC value to estimate the I/Q imbalance for the third frequency. The formula indicates the average of DC terms for the first and second pilot signals.)
Accordingly, it would have been obvious to person of ordinary skill in the art before the
effective filing date of the claimed invention to combine Liu with Nayebi for the benefit
of having an apparatus to with direct current (DC) calibration support for the transceiver. Further benefit to combine to have a calibration apparatus that can compensates for both TX/RX IQMM and removes TX/RX DC offset.
As for claim 8, Nayebi discloses the calibration apparatus of claim 7,
wherein the channel estimation performed by the estimation circuit further comprises:
referring to the plurality (two or more pilot signals) of Tx-to-Rx loop (the TX path/ a loopback path/ the RX path) (received pilot signals may be observed at baseband of the RX path) at least one of an equivalent baseband
(Paragraph [0021] discloses “This disclosure encompasses numerous inventive principles relating to in-phase (I) and quadrature (Q) mismatch (IQMM) in quadrature transceivers. Some of the principles involve techniques for jointly estimating IQMM, which may include frequency-dependent IQMM (FD-IQMM), in both the transmit (TX) and receive (RX) paths of a quadrature transceiver. In some embodiments, two or more pilot signals may be applied at baseband to the TX path which may be coupled to the RX path through a loopback path. Different phase shifts may be applied to the pilot signals, for example, through the use of a phase shifter in the loopback path. The received pilot signals may be observed at baseband of the RX path and analyzed using various disclosed algorithms to estimate the IQMM in both the TX and RX paths.”)
Nayebi does not appear to explicitly disclose Tx total DC offset, Rx total DC offset. However, Liu discloses Tx total DC offset, Rx total DC offset (transmitter and receiver DC offset);
In a similar field of endeavor, (Liu discloses “In some implementations, the complex envelope of the training signal {tilde over (s)}(t)=s.sub.I(t)+j.Math.s.sub.Q(t)=μ.sub.t, and μ.sub.t=μ.sub.t.sup.I+μ.sub.t.sup.Q, which contains only DC terms due to the orthogonality of OFDM subcarriers, may be used to evaluate the effects of the transmitter and receiver DC offset. In some implementations, the value of Y.sub.k at k=0 may be evaluated to yield:” [Col. 15, Line 64 … Col. 16 line 8])
Accordingly, it would have been obvious to person of ordinary skill in the art before the
effective filing date of the claimed invention to combine Liu with Nayebi for the benefit
of having an apparatus to with direct current (DC) calibration support for the transceiver. Further benefit to combine to have a calibration apparatus that can compensates for both TX/RX IQMM and removes TX/RX DC offset.
As for claim 9, Nayebi discloses the calibration apparatus of claim 1,
wherein the calibration circuit comprises at least one of a Tx in-phase/quadrature (IQ) mismatch compensator circuit (an IQMM pre-compensator at the transmit path), an Rx IQ mismatch compensator circuit (IQMM may include estimating coefficients of an IQMM compensator at the receive path), a
(Paragraph [0005] discloses “Compensating for IQMM using the estimates of IQMM may include estimating coefficients of an IQMM pre-compensator at the transmit path. Compensating for IQMM using the estimates of IQMM may include estimating coefficients of an IQMM compensator at the receive path.”)
Nayebi does not appear to explicitly disclose Tx DC remover circuit, and Rx DC remover circuit. However, Liu discloses Tx direct current (DC) remover circuit (TX I/Q correction filter), and an Rx DC remover circuit (RX I/Q correction filter);
In a similar field of endeavor, (Liu discloses “In some implementations, the transmitter I/Q imbalance γ.sub.t, the receiver I/Q imbalance γ.sub.r, and the DC offset value μ.sub.t (which is related to the TXCL) may be determined using a 4-step calibration operation based on the example model 400 of FIG. 4. In some implementations, an example training signal defined as {tilde over (s)}(t)=e.sup.jω.sup.k.sup.t may be transmitted through the transmit path 410 and the receive path 420 (via the loopback path 430) to generate the receive output signal {tilde over (y)}(t). [Col. 16, Line 17-24]”
Liu discloses “In some implementations, the TX I/Q correction filter 512 and the RX I/Q correction filter 526 each may be a complex FIR filter. In some implementations, the TX I/Q correction filter 512 and the RX I/Q correction filter 526 each may remove frequency-dependent I/Q imbalances using an n-tap I/Q correction filter, for example, by determining an output x according to the following relation: [Col. 19, Line 66 … Col. 20, line 5]”
TX/RX I/Q correction filter remove FD- IQ imbalances, the correction includes DC offset value.)
Accordingly, it would have been obvious to person of ordinary skill in the art before the
effective filing date of the claimed invention to combine Liu with Nayebi for the benefit
of having an apparatus to with direct current (DC) calibration support for the transceiver. Further benefit to combine to have a calibration apparatus that can compensates for both TX/RX IQMM and removes TX/RX DC offset.
As for claim 18, The calibration method of claim 12,
wherein performing the channel estimation according to at least the loop back receiving signal comprises: estimating a plurality (two or more pilot signals) of Tx-to-Rx loop (the TX path, loopback path/ phase shifter, the RX path) (the gain and/or phase shift), respectively.
(Paragraph [0021] discloses “This disclosure encompasses numerous inventive principles relating to in-phase (I) and quadrature (Q) mismatch (IQMM) in quadrature transceivers. Some of the principles involve techniques for jointly estimating IQMM, which may include frequency-dependent IQMM (FD-IQMM), in both the transmit (TX) and receive (RX) paths of a quadrature transceiver. In some embodiments, two or more pilot signals may be applied at baseband to the TX path which may be coupled to the RX path through a loopback path. Different phase shifts may be applied to the pilot signals, for example, through the use of a phase shifter in the loopback path. The received pilot signals may be observed at baseband of the RX path and analyzed using various disclosed algorithms to estimate the IQMM in both the TX and RX paths.”
Paragraph [0036] discloses “In some embodiments, the gain and/or phase shift applied by the phase shifter may be estimated as one or more unknowns in the system of equations. This may enable TX and RX IQMM parameters to be estimated without a priori knowledge of the phase shift.”)
Nayebi does not appear to explicitly disclose total direct current (DC) values by averaging the loop back receiving signal. However, Liu discloses total direct current (DC) values (DC terms) by averaging the loop back receiving signal (The third frequency-domain output signal may be expressed as a function of the first and second frequency-domain output signals).
In a similar field of endeavor, (Liu discloses “In the first step, the training signal is transmitted through the calibration path of the transceiver (such as through the transceiver's calibration path) at a tone k with the phase shifter 432 operating in the bypass state, for example, where S.sub.k=1 and S.sub. −k=0. Using the above-derived frequency-domain representations of the training signal, it may be shown that Y.sub.k(ϕ.sub.0) ≅C.sub.k (ϕ.sub.0) and that:
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where ϕ.sub.0 is the phase of the phase shifter 432 when operating in the bypass state. The DC terms may be expressed as:
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The channel response at DC may be approximated by measuring a tone m near the DC tone, where the value of m may be an integer (such as 1 or 2). Because C.sub.0(ϕ.sub.0)≅Y.sub.m(ϕ.sub.0), the DC terms may be rewritten, without the phase shift introduced by the phase shifter 432, as:
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[Col. 16, Line 25-44]”
Liu discloses “Although the DC tone values of the first frequency-domain output signal {Y.sub.k.sup.P(ϕ.sub.0)} and the second frequency-domain output signal {Y.sub.k.sup.N(ϕ.sub.0)} may differ because of the insertion of the first and second known TXCL correction values +Δ and −Δ into the first and second FDMT waveforms, respectively, other tone values of the first and second frequency-domain output signals remain constant (excluding variation in noise). The third frequency-domain output signal may be expressed as a function of the first and second frequency-domain output signals, for example, using the expression
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The resulting value {Y.sub.k(ϕ.sub.0)} may be combined with the value {Y.sub.k(ϕ.sub.1)} to estimate the transmitter I/Q imbalance and the receiver I/Q imbalance contemporaneously. [Col. 22, Line 43-62]”
Liu defined the expression to determine DC value(s) with/without a phase shifter for each signal traverse the loopback path. Liu further discloses the resulting DC values for signal N and P can result in an average DC value to estimate the I/Q imbalance for the third frequency. The formula indicates the average of DC terms for the first and second pilot signals.)
Accordingly, it would have been obvious to person of ordinary skill in the art before the
effective filing date of the claimed invention to combine Liu with Nayebi for the benefit
of having an apparatus to with direct current (DC) calibration support for the transceiver. Further benefit to combine to have a calibration apparatus that can compensates for both TX/RX IQMM and removes TX/RX DC offset.
As for claim 19, The calibration method of claim 18,
wherein performing the channel estimation according to at least the loop back receiving signal further comprises: referring to the plurality (two or more pilot signals) of Tx-to-Rx loop (the TX path/ a loopback path/ the RX path) (received pilot signals may be observed at baseband of the RX path) at least one of an equivalent baseband
(Paragraph [0021] discloses “This disclosure encompasses numerous inventive principles relating to in-phase (I) and quadrature (Q) mismatch (IQMM) in quadrature transceivers. Some of the principles involve techniques for jointly estimating IQMM, which may include frequency-dependent IQMM (FD-IQMM), in both the transmit (TX) and receive (RX) paths of a quadrature transceiver. In some embodiments, two or more pilot signals may be applied at baseband to the TX path which may be coupled to the RX path through a loopback path. Different phase shifts may be applied to the pilot signals, for example, through the use of a phase shifter in the loopback path. The received pilot signals may be observed at baseband of the RX path and analyzed using various disclosed algorithms to estimate the IQMM in both the TX and RX paths.”)
Nayebi does not appear to explicitly disclose Tx total DC offset, Rx total DC offset. However, Liu discloses Tx total DC offset, Rx total DC offset (transmitter and receiver DC offset);
In a similar field of endeavor, (Liu discloses “In some implementations, the complex envelope of the training signal {tilde over (s)}(t)=s.sub.I(t)+j.Math.s.sub.Q(t)=μ.sub.t, and μ.sub.t=μ.sub.t.sup.I+μ.sub.t.sup.Q, which contains only DC terms due to the orthogonality of OFDM subcarriers, may be used to evaluate the effects of the transmitter and receiver DC offset. In some implementations, the value of Y.sub.k at k=0 may be evaluated to yield:” [Col. 15, Line 64 … Col.16 line 8])
Accordingly, it would have been obvious to person of ordinary skill in the art before the
effective filing date of the claimed invention to combine Liu with Nayebi for the benefit
of having an apparatus to with direct current (DC) calibration support for the transceiver. Further benefit to combine to have a calibration apparatus that can compensates for both TX/RX IQMM and removes TX/RX DC offset.
As for claim 20, The calibration method of claim 12,
wherein performing the calibration upon the transceiver according to the at least one estimated value comprises: performing at least one of calibration operations that comprise a Tx in-phase/quadrature (IQ) mismatch compensation (an IQMM pre-compensator at the transmit path), an Rx IQ mismatch compensation (IQMM may include estimating coefficients of an IQMM compensator at the receive path),
(Paragraph [0005] discloses “Compensating for IQMM using the estimates of IQMM may include estimating coefficients of an IQMM pre-compensator at the transmit path. Compensating for IQMM using the estimates of IQMM may include estimating coefficients of an IQMM compensator at the receive path.”)
Nayebi does not appear to explicitly disclose Tx DC remover circuit, and Rx DC remover circuit. However, Liu discloses Tx direct current (DC) remover circuit (TX I/Q correction filter), and an Rx DC remover circuit (RX I/Q correction filter);
In a similar field of endeavor, (Liu discloses “In some implementations, the transmitter I/Q imbalance γ.sub.t, the receiver I/Q imbalance γ.sub.r, and the DC offset value μ.sub.t (which is related to the TXCL) may be determined using a 4-step calibration operation based on the example model 400 of FIG. 4. In some implementations, an example training signal defined as {tilde over (s)}(t)=e.sup.jω.sup.k.sup.t may be transmitted through the transmit path 410 and the receive path 420 (via the loopback path 430) to generate the receive output signal {tilde over (y)}(t). [Col. 16, Line 17-24]”
Liu discloses “In some implementations, the TX I/Q correction filter 512 and the RX I/Q correction filter 526 each may be a complex FIR filter. In some implementations, the TX I/Q correction filter 512 and the RX I/Q correction filter 526 each may remove frequency-dependent I/Q imbalances using an n-tap I/Q correction filter, for example, by determining an output x according to the following relation: [Col. 19, Line 66 … Col. 20, line 5]”
TX/RX I/Q correction filter remove FD- IQ imbalances, the correction includes DC offset value.)
Accordingly, it would have been obvious to person of ordinary skill in the art before the
effective filing date of the claimed invention to combine Liu with Nayebi for the benefit
of having an apparatus to with direct current (DC) calibration support for the transceiver. Further benefit to combine to have a calibration apparatus that can compensates for both TX/RX IQMM and removes TX/RX DC offset.
Claims 10 and 21 are rejected under 35 U.S.C. 103 as being unpatentable over Nayebi as applied to in view of Abdollahi-Alibeik et al., US Patent No. 8295845, filed on 12/4/2008 (hereinafter Abdollahi).
As for claim 10, The calibration apparatus of claim 1,
wherein the calibration is on-the-fly calibration (two or more pilot signals), and the loop back receiving signal (loopback path) is generated in response to a baseband input of the Tx (baseband of the TX path) of the transceiver that is .
(Paragraph [0021] discloses “This disclosure encompasses numerous inventive principles relating to in-phase (I) and quadrature (Q) mismatch (IQMM) in quadrature transceivers. Some of the principles involve techniques for jointly estimating IQMM, which may include frequency-dependent IQMM (FD-IQMM), in both the transmit (TX) and receive (RX) paths of a quadrature transceiver. In some embodiments, two or more pilot signals may be applied at baseband to the TX path which may be coupled to the RX path through a loopback path. Different phase shifts may be applied to the pilot signals, for example, through the use of a phase shifter in the loopback path. The received pilot signals may be observed at baseband of the RX path and analyzed using various disclosed algorithms to estimate the IQMM in both the TX and RX paths.”
Current invention discloses calibration on-the-fly (OTF) also known as background calibration. The baseband input is a non-modulation signal (e.g., a pseudo random code (PNC) signal, a single-tone signal, or a multi-tone signal) that is specific to the calibration task and carries no valid user data. The claim indicates a modulation signal.)
Nayebi does not appear to explicitly disclose modulation signal. However, Abdollahi discloses a modulation signal (OFDM signals)
In a similar field of endeavor, (Abdollahi discloses “During a calibration mode of operation, the loopback switch115 is closed, and the transmitter unit 110 provides a first signal and a second signal to the receiver unit 150 via the loopback path 105, as noted at stage A. In one implementation, the phase shift unit 125 adds a phase shift to the second signal provided to the receiver unit 150, as noted at stage B. In one example, the transmitter unit 110 provides the first signal to the receiver unit 150 without intentionally adding a phase shift. In other words, for transmission of the first signal, the switch connected to the phase shift unit 125 may be opened to bypass the phase shift unit 125. In one example, the switch of the phase shift unit 125 may be opened and closed by the transmitter pre-distortion unit 145 or the I/Q mismatch calibration unit 185 or other control entity of the transceiver 100. After transmission of the first signal, in one example, the switch of the phase shift unit 125 is closed, and the transmitter unit 110 provides a second signal to the receiver unit 150 with a phase shift added by the phase shift unit 125, as will be described further below with reference to FIGS. 2-4. In some implementations, the first and second signals may be OFDM signals or pilot tones, e.g., generated by the transmitter baseband processor 140. It is noted, however, that in other implementations, the transmitter unit 110 may generate other types of signals for the calibration operations of the transceiver 100. [Col. 3, line 7-31]”
OFDM divides the incoming bitstream into multiple streams, each modulated with bits from the incoming stream.)
Accordingly, it would have been obvious to person of ordinary skill in the art before the
effective filing date of the claimed invention to combine Abdollahi with Nayebi for the benefit
of having a transceivers apparatus support both non-modulate and modulate test signals. Further benefit to combine is to reuse the loopback capabilities using loop gains to estimate and repair IQMM and DC imbalances.
As for claim 21, Nayebi discloses the calibration method of claim 12,
wherein the calibration is on-the-fly calibration (two or more pilot signals), and the loop back receiving signal (loopback path) is generated in response to a baseband input of the Tx (baseband of the TX path) of the transceiver that is a
(Paragraph [0021] discloses “This disclosure encompasses numerous inventive principles relating to in-phase (I) and quadrature (Q) mismatch (IQMM) in quadrature transceivers. Some of the principles involve techniques for jointly estimating IQMM, which may include frequency-dependent IQMM (FD-IQMM), in both the transmit (TX) and receive (RX) paths of a quadrature transceiver. In some embodiments, two or more pilot signals may be applied at baseband to the TX path which may be coupled to the RX path through a loopback path. Different phase shifts may be applied to the pilot signals, for example, through the use of a phase shifter in the loopback path. The received pilot signals may be observed at baseband of the RX path and analyzed using various disclosed algorithms to estimate the IQMM in both the TX and RX paths.”
Current invention discloses calibration on-the-fly (OTF) also known as background calibration. The baseband input is a non-modulation signal (e.g., a pseudo random code (PNC) signal, a single-tone signal, or a multi-tone signal) that is specific to the calibration task and carries no valid user data. The claim indicates a modulation signal.)
Nayebi does not appear to explicitly disclose modulation signal. However, Abdollahi discloses a modulation signal (OFDM signals)
In a similar field of endeavor, (Abdollahi discloses “During a calibration mode of operation, the loopback switch115 is closed, and the transmitter unit 110 provides a first signal and a second signal to the receiver unit 150 via the loopback path 105, as noted at stage A. In one implementation, the phase shift unit 125 adds a phase shift to the second signal provided to the receiver unit 150, as noted at stage B. In one example, the transmitter unit 110 provides the first signal to the receiver unit 150 without intentionally adding a phase shift. In other words, for transmission of the first signal, the switch connected to the phase shift unit 125 may be opened to bypass the phase shift unit 125. In one example, the switch of the phase shift unit 125 may be opened and closed by the transmitter pre-distortion unit 145 or the I/Q mismatch calibration unit 185 or other control entity of the transceiver 100. After transmission of the first signal, in one example, the switch of the phase shift unit 125 is closed, and the transmitter unit 110 provides a second signal to the receiver unit 150 with a phase shift added by the phase shift unit 125, as will be described further below with reference to FIGS. 2-4. In some implementations, the first and second signals may be OFDM signals or pilot tones, e.g., generated by the transmitter baseband processor 140. It is noted, however, that in other implementations, the transmitter unit 110 may generate other types of signals for the calibration operations of the transceiver 100. [Col. 3, line 7-31]”
OFDM divides the incoming bitstream into multiple streams, each modulated with bits from the incoming stream.)
Accordingly, it would have been obvious to person of ordinary skill in the art before the
effective filing date of the claimed invention to combine Abdollahi with Nayebi for the benefit
of having a transceivers apparatus support both non-modulate and modulate test signals. Further benefit to combine is to reuse the loopback capabilities using loop gains to estimate and repair IQMM and DC imbalances.
Conclusion
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/JOSEPH KHANH NGUYEN/Examiner, Art Unit 2646
/CHARLES N APPIAH/Supervisory Patent Examiner, Art Unit 2641
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