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
Claims 1-13 are currently pending.
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55. The certified copy has been filed in parent Application Number. DE10 2021 116 549.0, filed on June 25, 2021.
Information Disclosure Statement
The information disclosure statement (IDS) submitted on December 18, 2023 is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
Claim Rejections - 35 USC § 103
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 of this title, 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.
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.
Claims 1 and 3-13 are rejected under 35 U.S.C. 103 as being unpatentable over Zhao et al. (US 2009/0103666 A1) in view of Sikri et al. (US 2013/0128942 A1)
Regarding claim 1, Zhao discloses a method of determining symbols transmitted in a transmission block (S[k]) over a wireless channel using orthogonal frequency division multiplex, the transmission block (S[k]) comprising at least one data sub-block and at least one pilot sub-block, the method comprising (Fig. 1, paragraph 0059 discloses a discrete-time OFDM system 10 with N subcarriers is shown in FIG. 1. The information bits {b.sup.(i)} are first encoded 12 into coded bits sequences {d.sup.(i)}, where i is the time index. These coded bits are interleaved 14 into a new sequence of {c.sup.(i)}, mapped 16 into M-ary complex symbols and serial-to-parallel (S/P) converted 18 to a data sequence. Pilot sequences are inserted 20 into data sequences):
a) receiving, in the frequency domain, a transmission block (Y[k]) transmitted via the OFDM transmission channel (Fig. 1, paragraph 0059-60 FIG. 1, it also shows the receiver structure for turbo processing used in channel estimation. In this example, the feedback information, which is the estimation of the probability of coded data bits, is fed back to the channel estimator 60);
b) performing a pilot-aided first channel estimation function on the received transmission block (Y[k]) (Fig. 1, paragraph 0078 discloses in the iterative turbo channel estimation, preamble, pilot and soft coded data symbols are used in three stages, which are referred to as the initial coarse estimation stage, the iterative estimation stage, and the final maximum likelihood or minimum mean square error estimation stage. We assume that OFDM symbols are transmitted continuously on a frame basis. Each OFDM frame consists of an OFDM symbol working as a preamble followed by a number of other OFDM data symbols. In the OFDM data symbols, pilot tones are evenly distributed across all available subcarriers);
c) providing the received transmission block (Y[k]) and the output (hq(/)1) of the pilot-aided first channel estimation function to a first channel equalisation function, wherein an output of the first channel equalisation function is a set of first-iteration estimated symbols (S[k]i), (Paragraph 0079-0081 discloses the initial coarse estimation stage is performed at the first iteration. Frequency and time domain MAW filtering is performed on the estimates from the preamble symbol and pilot tones are applied to obtain the initial coarse channel frequency response. The correlation between the channels occupied by pilots and those occupied by data allows pilot-aid channel estimation to work effectively);
d) providing the received transmission block (Y[k]) and the set of first- iteration estimated symbols (S[k]1) to a data-aided second channel estimation function (Paragraph 0043 discloses a decoding processor to decode a symbol of the received transmission by retrieving pilot tones from it and using these to estimate variations in the channel frequency response using an iterative maximum likelihood channel estimation process)
e) providing the received transmission block (Y[k]), the set of first-iteration estimated symbols (S[k]1) and the output (hq(/)i) of the data-aided second channel estimation function (Paragraph 0043 discloses a decoding processor to decode a symbol of the received transmission by retrieving pilot tones from it and using these to estimate variations in the channel frequency response using an iterative maximum likelihood channel estimation process) to an adjustable interference cancellation function (IC) (Paragraph 0086 discloses The channel estimator 60 will compute the soft coded data information based on LLR as in "Iterative (turbo) soft interference cancellation);
Zhao does not explicitly disclose the following limitations: f) providing the output (hq(/)i) of the data-aided second channel estimation function and the output (Y'[k]) of the adjustable interference cancellation function (IC) to a second equaliser function, wherein an output of the second equaliser function is a set of i-th-iteration estimated symbols (S[k]i), i being larger than 1, wherein each set of i-th-iteration estimated symbols (S[k]i) may include the set of the estimated symbols (S[k]i-1) from the previous iteration as a subset; g) repeating steps e) and f), wherein the received transmission block (Y[k]) and the i-th-iteration set of estimated symbols (S[k]i) is iteratively provided to the data- aided second channel estimation function and the adjustable interference cancellation function (IC), respectively, until a predetermined termination condition is fulfilled.
In an analogous art, Sikri discloses
f) providing the output (hq(/)i) of the data-aided second channel estimation function and the output (Y'[k]) of the adjustable interference cancellation function (IC) to a second equaliser function, wherein an output of the second equaliser function is a set of i-th-iteration estimated symbols (S[k]i), i being larger than 1, wherein each set of i-th-iteration estimated symbols (S[k]i) may include the set of the estimated symbols (S[k]i-1) from the previous iteration as a subset (Paragraph 0087 discloses multi-stream equalization and interference cancellation with the pre-coding/pre-decoding schemes described above to provide a low complexity receiver that performs well in the presence of interference. Aspects of the present disclosure employ interference cancellation in the time domain for interference cancellation within an OFDM radio access technology framework. Fig. 6, paragraph 0115 discloses in block 606, cancellation of co-channel interference is performed with a multipoint equalization block in the time domain using the first-time domain channel estimate. In block 608, cancellation of a residual inter-symbol interference is performed by a first cyclic coordinate ascend section in the time domain. In block 610, a cancellation of inter-carrier interference on the received OFDM signal is performed by a second cyclic coordinate second section in the frequency domain. The references symbols {tilde over (d)} are provided iteratively to the CCAt block 518 by a multiplexer block 530. The estimate for the ISI cancelled symbol s.sub.k is represented by Equation 20.)
g) repeating steps e) and f), wherein the received transmission block (Y[k]) and the i-th-iteration set of estimated symbols (S[k]i) is iteratively provided to the data- aided second channel estimation function and the adjustable interference cancellation function (IC), respectively, until a predetermined termination condition is fulfilled (Fig. 6, Paragraphs 0095-0096, 0115-0116 disclose the processor(s) is also configured to transform the first frequency domain channel estimate to a first time domain channel estimate and to perform a cancellation of co-channel interference with a multipoint equalization block in the time domain using the first time domain channel estimate. The processor(s) is also configured to perform a cancellation of residual inter-symbol interference by a first cyclic coordinate ascend section in the time domain and to perform a cancellation of inter-carrier interference on the received OFDM signal by a second cyclic coordinate ascend section in the frequency domain).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide the technique of Sikri to the system of Zhao to provide wireless communication system that relates to interference cancellation at a receiver (Abstract, Sikri).
Regarding claim 7, Zhao discloses An OFDM receiver having a first channel estimation block adapted to perform a pilot-aided channel estimation on a received transmission block (Y[k]) in the frequency domain (Fig. 1 discloses the structure of a receiver, paragraph 0059 discloses a discrete-time OFDM system 10 with N subcarriers is shown in FIG. 1. The information bits {b.sup.(i)} are first encoded 12 into coded bits sequences {d.sup.(i)}, where i is the time index. These coded bits are interleaved 14 into a new sequence of {c.sup.(i)}, mapped 16 into M-ary complex symbols and serial-to-parallel (S/P) converted 18 to a data sequence. Pilot sequences are inserted 20 into data sequences),
an output of which first channel estimation block is provided, along with the received signal (Y[k]) in the frequency domain, to a first equaliser block (Fig. 1, paragraph 0078 discloses in the iterative turbo channel estimation, preamble, pilot and soft coded data symbols are used in three stages, which are referred to as the initial coarse estimation stage, the iterative estimation stage, and the final maximum likelihood or minimum mean square error estimation stage. We assume that OFDM symbols are transmitted continuously on a frame basis. Each OFDM frame consists of an OFDM symbol working as a preamble followed by a number of other OFDM data symbols. In the OFDM data symbols, pilot tones are evenly distributed across all available subcarriers), wherein an output of the first equaliser block is provided, along with the received signal (Y[k]) in the frequency domain, to a second channel estimation block, adapted to perform a data-aided channel estimation on a received transmission block (Paragraph 0079-0081 discloses the initial coarse estimation stage is performed at the first iteration. Frequency and time domain MAW filtering is performed on the estimates from the preamble symbol and pilot tones are applied to obtain the initial coarse channel frequency response. The correlation between the channels occupied by pilots and those occupied by data allows pilot-aid channel estimation to work effectively), wherein an output of the second channel estimation block is provided, along with the output (S[k]1) of the first equaliser block (Paragraph 0043 discloses a decoding processor to decode a symbol of the received transmission by retrieving pilot tones from it and using these to estimate variations in the channel frequency response using an iterative maximum likelihood channel estimation process) to an adjustable interference cancellation function (IC) (Paragraph 0086 discloses The channel estimator 60 will compute the soft coded data information based on LLR as in "Iterative (turbo) soft interference cancellation) and the received transmission block (Y[k]) in the frequency domain, to an interference cancellation block IC (Paragraph 0043 discloses a decoding processor to decode a symbol of the received transmission by retrieving pilot tones from it and using these to estimate variations in the channel frequency response using an iterative maximum likelihood channel estimation process),
Zhao does not explicitly disclose the following limitations
wherein the output (Y'[k]) of the interference cancellation block (IC) and the output (hq(i) i=2) of the second channel estimation block are provided to a second equaliser block,
wherein the output (S[k],i=2) of the second equaliser block is provided to a de-mapping block, and is provided to the second channel estimation block and the interference cancellation block (IC), for allowing an iterative repetition of channel estimation, interference cancellation and equalisation for a received transmission block (Y[k]) in the frequency domain.
In an analogous art, Sikri discloses
wherein the output (Y'[k]) of the interference cancellation block (IC) and the output (hq(i) i=2) of the second channel estimation block are provided to a second equaliser block (Paragraph 0087 discloses multi-stream equalization and interference cancellation with the pre-coding/pre-decoding schemes described above to provide a low complexity receiver that performs well in the presence of interference. Aspects of the present disclosure employ interference cancellation in the time domain for interference cancellation within an OFDM radio access technology framework. Fig. 6, paragraph 0115 discloses in block 606, cancellation of co-channel interference is performed with a multipoint equalization block in the time domain using the first-time domain channel estimate. In block 608, cancellation of a residual inter-symbol interference is performed by a first cyclic coordinate ascend section in the time domain. In block 610, a cancellation of inter-carrier interference on the received OFDM signal is performed by a second cyclic coordinate second section in the frequency domain. The references symbols {tilde over (d)} are provided iteratively to the CCAt block 518 by a multiplexer block 530. The estimate for the ISI cancelled symbol s.sub.k is represented by Equation 20).
Regarding claim 12, Zhao discloses
An OFDM receiver having a first channel estimation block adapted to perform a pilot-aided channel estimation on a received transmission block (Y[k]) in the frequency domain (Fig. 1, paragraph 0059 discloses a discrete-time OFDM system 10 with N subcarriers is shown in FIG. 1. The information bits {b.sup.(i)} are first encoded 12 into coded bits sequences {d.sup.(i)}, where i is the time index. These coded bits are interleaved 14 into a new sequence of {c.sup.(i)}, mapped 16 into M-ary complex symbols and serial-to-parallel (S/P) converted 18 to a data sequence. Pilot sequences are inserted 20 into data sequences),
an output of which first channel estimation block is provided, along with the received signal in the frequency domain, to a first equaliser block (Fig. 1, paragraph 0078 discloses in the iterative turbo channel estimation, preamble, pilot and soft coded data symbols are used in three stages, which are referred to as the initial coarse estimation stage, the iterative estimation stage, and the final maximum likelihood or minimum mean square error estimation stage. We assume that OFDM symbols are transmitted continuously on a frame basis. Each OFDM frame consists of an OFDM symbol working as a preamble followed by a number of other OFDM data symbols. In the OFDM data symbols, pilot tones are evenly distributed across all available subcarriers), wherein an output of the first equaliser block is provided, along with the received signal in the frequency domain, to a second channel estimation block, adapted to perform a data-aided channel estimation on a received transmission block (Paragraph 0079-0081 discloses the initial coarse estimation stage is performed at the first iteration. Frequency and time domain MAW filtering is performed on the estimates from the preamble symbol and pilot tones are applied to obtain the initial coarse channel frequency response. The correlation between the channels occupied by pilots and those occupied by data allows pilot-aid channel estimation to work effectively), wherein an output of the second channel estimation block is provided, along with the output of the first equaliser block (Paragraph 0043 discloses a decoding processor to decode a symbol of the received transmission by retrieving pilot tones from it and using these to estimate variations in the channel frequency response using an iterative maximum likelihood channel estimation process) to an adjustable interference cancellation function (Paragraph 0086 discloses The channel estimator 60 will compute the soft coded data information based on LLR as in "Iterative (turbo) soft interference cancellation) and the received transmission block in the frequency domain, to an interference cancellation block IC (Paragraph 0043 discloses a decoding processor to decode a symbol of the received transmission by retrieving pilot tones from it and using these to estimate variations in the channel frequency response using an iterative maximum likelihood channel estimation process),
Zhao does not explicitly disclose the following limitations
a non-transitory computer program product comprising computer program instructions which, when executed by a microprocessor, cause the computer, and/or control hardware components of an OFDM receiver;
wherein the output of the interference cancellation block (IC) and the output of the second channel estimation block are provided to a second equaliser block,
wherein the output of the second equaliser block is provided to a de-mapping block, and is provided to the second channel estimation block and the interference cancellation block, for allowing an iterative repetition of channel estimation, interference cancellation and equalisation for a received transmission block (Y[k]) in the frequency domain.
In an analogous art, Sikri discloses a non-transitory computer program product comprising computer program instructions which, when executed by a microprocessor, cause the computer, and/or control hardware components of an OFDM receiver (Paragraph 0116 discloses wireless communication apparatus includes receive processor 238, the control processor 240 and/or the memory 242 configured to perform the functions recited by the means. The receive processor 238, the control processor 240 and/or the memory 242 are also examples of the means for performing a cancellation of residual inter-symbol interference by a first cyclic coordinate ascend section in the time domain, and means for performing a cancellation of inter-carrier interference on the received OFDM signal by a second cyclic coordinate ascend section in the frequency domain)
wherein the output of the interference cancellation block and the output of the second channel estimation block are provided to a second equaliser block (Paragraph 0087 discloses multi-stream equalization and interference cancellation with the pre-coding/pre-decoding schemes described above to provide a low complexity receiver that performs well in the presence of interference. Aspects of the present disclosure employ interference cancellation in the time domain for interference cancellation within an OFDM radio access technology framework. Fig. 6, paragraph 0115 discloses in block 606, cancellation of co-channel interference is performed with a multipoint equalization block in the time domain using the first-time domain channel estimate. In block 608, cancellation of a residual inter-symbol interference is performed by a first cyclic coordinate ascend section in the time domain. In block 610, a cancellation of inter-carrier interference on the received OFDM signal is performed by a second cyclic coordinate second section in the frequency domain. The references symbols {tilde over (d)} are provided iteratively to the CCAt block 518 by a multiplexer block 530. The estimate for the ISI cancelled symbol s.sub.k is represented by Equation 20.),
wherein the output of the second equaliser block is provided to a de-mapping block, and is provided to the second channel estimation block and the interference cancellation block, for allowing an iterative repetition of channel estimation, interference cancellation and equalisation for a received transmission block in the frequency domain (Fig. 6, Paragraphs 0095-0096, 0115-0116 disclose the processor(s) is also configured to transform the first frequency domain channel estimate to a first time domain channel estimate and to perform a cancellation of co-channel interference with a multipoint equalization block in the time domain using the first time domain channel estimate. The processor(s) is also configured to perform a cancellation of residual inter-symbol interference by a first cyclic coordinate ascend section in the time domain and to perform a cancellation of inter-carrier interference on the received OFDM signal by a second cyclic coordinate ascend section in the frequency domain).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide the technique of Sikri to the system of Zhao to provide wireless communication system that relates to interference cancellation at a receiver (Abstract, Sikri).
Regarding claim 13, the combination of Zhao and Sikri, specifically Sikri discloses a non-transitory computer readable-medium retrievably storing the computer program product of claim 12 receiver (Paragraph 0116 discloses wireless communication apparatus includes receive processor 238, the control processor 240 and/or the memory 242 configured to perform the functions recited by the means. The receive processor 238, the control processor 240 and/or the memory 242 are also examples of the means for performing a cancellation of residual inter-symbol interference by a first cyclic coordinate ascend section in the time domain, and means for performing a cancellation of inter-carrier interference on the received OFDM signal by a second cyclic coordinate ascend section in the frequency domain)
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide the technique of Sikri to the system of Zhao to provide wireless communication system that relates to interference cancellation at a receiver (Abstract, Sikri).
Regarding claims 3 and 8, Zhao discloses wherein the pilot-aided first channel estimation function and/or the data-aided second channel estimation function apply a basis expansion model (Paragraph [0018] Approximating a LMMSE estimation by representing the channel in basis expansion model (BEM) and obtaining the channel impulse response from interpolation of partial channel information using discrete orthogonal legendre polynomials).
Regarding claims 4 and 9, Zhao discloses wherein the first channel equalisation function implements a message passing or a minimum mean square error equaliser (Paragraph [0078] wherein after the second and subsequent iterations a minimum mean-square error (MMSE) principle is used to obtain the final channel estimates).
Regarding claims 5 and 10, Zhao discloses wherein the second channel equalisation function implements a maximum likelihood sequence estimation (MLSE) equaliser. (Paragraph 0116 discloses a maximum likelihood estimator in the time domain, which is basically a least square (LS) approach over all pilot subcarriers).
Regarding claim 11, Zhao discloses A wireless device with an OFDM receiver according to claim 7 (Fig. 1, paragraph 0059).
Regarding claim 6, Zhao discloses wherein the interference cancellation function (IC) is adjustable and is arranged to cancel the intercarrier interference on the non-zero sub-diagonals and super diagonals of the channel matrix (H) in the frequency domain and to convert the channel matrix (H) into a banded diagonal matrix (Hb) with a dispersion width smaller than that of the original channel matrix (H) (Paragraph 0066-0068, 0088, 0103 discloses the mechanism of diagonal matrix, need to estimate the diagonal terms [H.sup.(i)].sub.m,m. The off-diagonal terms [H.sup.(i)].sub.m,k causing ICI in can be ignored in the estimation if f.sub.mT.sub.sym.ltoreq.0.08 because the signal-to-interference ratio (SIR) will be above 20 dB. To verify this, we calculate the cross-correlation between any elements in the H.sup.(i) matrix).
Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over Zhao et al in view of Sikri et al. and further in view of Medra et al. (US 2020/0106648 A1).
Regarding claim 2, the combination of Zhao and Sikri do not specifically disclose wherein the first channel equalisation function has a computational complexity or performance that is lower than that of the second channel equalisation function.
In an analogous art, Medra discloses wherein the first channel equalisation function has a computational complexity or performance that is lower than that of the second channel equalisation function (Paragraph 0089, DFE may be especially useful with severely distorted channels, for example, when the roots of the Z-transform of the channel impulse response are close to the unit circle. The computational complexity of the DFE method is also relatively low compared to the BCJR and MLSE methods).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide the technique of Medra to the modified system of Zhao and Sikri to provide systems and methods for equalization of distorted signals, and in particular embodiments to noise whitening post-compensation for narrowband-filtered signals (Abstract, Medra).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
Gatti et al. (US 2013/0064313 A1) discloses estimating the channel impulse response in Orthogonal Frequency Division Multiplexing (OFDM) systems experiencing fading channels. In another embodiment, the channel length also can be estimated jointly with the channel impulse response
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/ROMANI OHRI/Primary Examiner, Art Unit 2413