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 .
Claim Rejections - 35 USC § 102
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)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claims 1-20 are rejected under 35 U.S.C. 102(a)(2) as being anticipated by Ota Atscushi et. al. (JP Pub.: JP2012222455A, translated version, hereinafter “Ota”).
Regarding claim 1, Ota teaches that a communication system comprising: a transmission station; a reception station; one or more relay stations configured to relay a first signal from the transmission station to the reception station without demodulating or decoding the first signal; and (Ota, in Page 2, Lines 28-36 and in Page 3, Lines 1-13, teaches that due to a demand for lower power consumption of infrastructure including wireless communication, coherent transmission with a plurality of relay stations interposed is effective. Coherent transmission does not depend on whether the form of the relay is non-regenerative relay (without decoding or demodulation) or regenerative relay (with decoding, demodulation, or both) but it is important that each signal to transmit is synthesized in the same phase on the receiving side. Thus, although this art is described based on regenerative relay, the method can be applied to non-regenerative relay, too. For the wireless relay system, when a plurality of relay stations is connected to one base station, the base station and the relay station corresponds to the control station and the antenna of the distributed antenna system, respectively. The base station (transmission station, also include a control station) and the relay station are connected by radio. By performing coherent transmission, a plurality of antennas (relay stations) transmit and the signals are combined in the same phase on the receiving terminal side (reception station).) a controller configured to acquire, for at least a first relay station among the one or more relay stations, a first delay time and a first phase rotation amount to be provided to the first signal in relay by the first relay station on a basis of radio propagation characteristics between the transmission station and the first relay station and radio propagation characteristics between the reception station and the first relay station (Ota, in Fig. 1 and in Page 23, Lines 16-37 and in Page 24, Lines 1-8, teaches that in Fig. 1, if the signals transmitted from the control station 2 (it can be a controller and a transmitter station) can be received by the wireless modules (relay stations) 3-1 to 3-6 at almost the same time and the signals received by the wireless modules are transmitted immediately, synchronization is achieved as a result. However, in reality, if the path length difference is known, the timing is adjusted by adjusting the delay time by the time obtained by dividing the path length difference by the speed of light. When the distance between the control station 2 and the wireless modules 3-1 to 3-6 is known and the control station 2 and the wireless modules 3-1 to 3-6 are connected by a wireless line, it is possible to grasp the propagation delay, and the same delay time can be adjusted. In addition to adjusting the delay time by adjusting the timing of actual transmission or reception processing back and forth, if the time to be adjusted, that is, the timing error is known by measurement or the like. It is also possible to estimate how much the amount of rotation of the complex phase of the wireless signal in the wireless communication system changes due to the time difference, and to cope with the correction process by canceling the amount of rotation. In this case, the correction means that the transmission weight or the reception weight is corrected/changed to a value considering the influence of the timing error. Namely, in order to perform the in-phase synthesis, the transmission weight and the reception weight may be corrected and changed based on relative values such as path difference length and timing error. As described in Fig. 2 and in Page 24, Lines 22-37, in Page 25, and in Page 26, Lines 1-6, to perform in-phase synthesis, the channel characteristics is provided by two-wave model (since it represents propagation delay and delay spread corresponding to the channel and can be considered as radio propagation characteristics) and two-way model is estimated by the method described in Page 25, Lines 17-32. For in-phase synthesis, based on this method, the channel characteristic between control station and wireless modules and the channel characteristics between wireless modules and reception station are acquired for the transmission weight (transmission filter) or the reception weight (reception filter), respectively. Based on the above, control station provides the delay time and phase rotation amount can be estimated and applied to the relay signal (the first signal) for the correction through transmission filtering and reception filtering.) so that one or more relay signals of the first signal relayed by the one or more relay stations arrive at the reception station at the same time and in the same phase after a first time length from a head of a slot in a radio frame which is synchronous among the transmission station, the reception station, and the one or more relay stations and in which the first signal is transmitted, and to cause the first relay station to provide the first delay time and the first phase rotation amount to the first signal (Ota, in Fig. 20 and in Page 3, Lines 15-32, teach that In FIG. 20, 101 is a transmitting station, 102-1 to 102-4 are relay stations, and 103 is a receiving station. Here, a form of a wireless relay system is shown, and it is assumed that there are a total of N relay stations 102-1 to 102-4. By using coherent transmission system and in-phase synthesis method described in the above, first, the transmitting station 101 once transmits a wireless packet addressed to the receiving station 103 to the relay stations 102-1 to 102-4. The relay stations 102-1 to 102-4 perform various received signal processing on the received signals, and reproduce (restore) the wireless packets transmitted by the transmitting station 101. Next, each relay station 102-1 to 102-4 transmits the reproduced same wireless packet to the receiving station 103 at the same time. At this time, a signal transmitted from each relay station is received by the receiving station 103. The phase of the transmission signal is adjusted so that the signals are received at the same phase. The receiving station 103 synthesizes and receives all the signals from these relay stations 102-1 to 102-4. Based on the coherent transmission system and in-phase synthesis technique, the delay time and phase rotation amount of relay signals are adjusted and applied to the relay signals based on the transmission filter (transmission weights) and the reception filter (reception weights) and it determines the first time length and maintains the synchronous relationship of a transmission station, relay stations, and a reception station.)
Regarding claim 2, Ota teaches the features defined in the claim 1, -refer to the indicated claim for reference(s).
Ota further teaches that wherein each of the one or more relay stations includes a first filter configured to perform filtering to suppress interference between a signal received from the transmission station and the signal to be transmitted to the reception station, the interference occurring in each of the one or more relay stations, and the first filter provides the first delay time to the first signal by the filtering and provides the first phase rotation amount to the first signal after the filtering. (Ota, in Fig. 25 and in Page 11, 31-36 and in Page 12, Lines 1-23, teaches that in Fig. 25, each analog signal is multiplied by signals input from local oscillators 175-1 to 175-3 by mixers 168-1 to 168-3, and is up-converted to a radio frequency signal. Since the signal here includes a signal also in the frequency component outside the band of the channel to be transmitted, the out-of-band component (it is a kind of interference between a signal received from transmission station and the signal to be transmitted to the reception station) is removed by the filters 169-1 to 169-3 (suppressing interference), and this is converted to the high power amplifiers 170-1 to 170-3, the signal is amplified and transmitted from the antennas 171-1 to 171-3. The signals transmitted from the wireless modules 176-1 to 176-3 are basically the same signals except that they are multiplied by different transmission weights (transmission filter). Phase synthesis can be realized (as shown in the above, this procedure includes adjusting delay time and phase rotation amount). The transmission weights multiplied by the transmission signal processing circuits 166-1 to 166-3 are separately acquired by the channel information acquisition circuits 172-1 to 172-3, and the channel information storage circuit 173 is updated sequentially. At the time of signal transmission, transmission weight calculation circuits 174-1 to 174-3 read channel information from channel information storage circuits 173-1 to 173-3, calculate transmission weights based on the information, and use these as transmission signals. Applying transmission weights (filtering) compensates the delay time and the phase rotation amount in in-phase synthesis technique and equalizes the relay signal (the first signal). Therefore, the filtering by the filters 169-1 to 169-3 and transmission filters 174-1 to 174-3 in relay station suppress interference (out of band interference and the inter-symbol interference due to delay time and phase rotation amount) of the input signal of the relay station and further, thru the transmission filtering, the delay time compensation and phase rotation amount correction is applied to the relay input signal (the first signal).)
Regarding claim 3, Ota teaches the features defined in the claim 1, -refer to the indicated claim for reference(s).
Ota further teaches that wherein the controller is configured to acquire the first delay time so that the relay signal of the first signal is transmitted from the first relay station after a second time length from the head of the slot, the second time length being obtained by subtracting a propagation delay between the first relay station and the reception station from the first time length (Ota, in Fig. 1 and 2 and in Page 23, Lines 16-37, in Page 24, Lines 1-8, in Page 24, Lines 22-37, in Page 25, and in Page 26, Lines 1-6, teaches that as described in Page 25, Lines 17-32, the channel information between a transmission station and the relay station is acquired, by the control station, using two-wave model and based on this information, the delay time information and phase rotation amount of the relay signal are estimated at the relay station. By using in-phase synthesis with transmission filter (weighting), the delay time and phase rotation amount are compensated or corrected. Then, ideally, the delay time between the relay station and the reception station becomes a delay of the processing time of relay station and a propagation delay between the relay station and the reception station. Therefore, if the processing time of the relay station is measured or known and further the relay station compensates this processing delay, the second time length can be zero and the relay station can send the relay signal without considering the second time length. Then, the condition of the claim can be satisfied by the control station.)
Regarding claim 4, Ota teaches the features defined in the claim 1, -refer to the indicated claim for reference(s).
Ota further teaches that wherein each of the one or more relay stations includes an antenna, and a transmitter and a receiver to be connected to the antenna, and (Ota, in Fig. 25, teaches that Fig. 25 shows that a relay station is connected with a transmit station and a reception station with antenna(s), respectively.) the controller is configured to acquire, as the first phase rotation amount, a value obtained by subtracting a phase rotation amount to be applied at the transmitter, a phase rotation amount to be applied on a propagation path from the transmission station to the first relay station, and a phase rotation amount to be applied on a propagation path from the first relay station to the reception station from a phase rotation amount to be applied at the receiver (Ota, in Fig. 2 and in Page 24, Lines 22-37, in Page 25, and in Page 26, Lines 1-6, teaches that as described in Page 25, Lines 17-32, the channel information between a transmission station and the relay station is acquired, by the control station, using two-wave model and based on this information, the delay time information and phase rotation amount between transmitter and the relay station are estimated at the relay station. This phase rotation amount can be considered as the sum of a phase rotation amount at the transmitter and a phase rotation amount to be applied on a propagation path from the transmission station to the relay station. In the relay station, as shown in the above, by the filtering, this phase rotation amount is compensated or corrected at the relay station. Then, at the reception station, by using the same method, the channel information (propagation path information) between the relay station and reception is estimated and based on this information, the phase rotation amount between the relay and the reception station is estimated or measured by the control station. Since the phase rotation amount measured in the relay station is already corrected or compensated (ideally, this amount is zero), the measured phase rotation amount between a relay station and the reception station becomes the phase rotation amount to be applied on a propagation path from the first relay station to the reception station and also, it becomes the first phase rotation amount.)
Regarding claim 5, Ota teaches the features defined in the claim 1, -refer to the indicated claim for reference(s).
Ota further teaches that wherein the controller is configured to: determine whether or not a relay signal of the first signal transmitted from the first relay station is able to arrive at the reception station within a first time length from the head of the slot on a basis of a propagation delay between the first relay station and the reception station; (Ota, in Fig. 1 and 2 and in Page 23, Lines 16-37, in Page 24, Lines 1-8, in Page 24, Lines 22-37, in Page 25, and in Page 26, Lines 1-6, teaches that as described in Page 25, Lines 17-32, the channel information between a transmission station and the relay station is acquired, by the control station, using two-wave model and based on this information, the delay time information and phase rotation amount between transmitter and the relay station are estimated at the relay station. Then, by in-phase synthesis technique and transmission filtering, the delay time between the transmitter and the relay station is compensated or corrected. Unless severe error occurred in channel information or the processing time of the relay station is too big, the relay signal is always arrived in the first time length due to compensation, if the delay time between the relay station and the reception station is not greater than the first time length. However, if at the relay station, the SNR of the received signal is too low (causing the severe error in the channel estimation), then, it might be occurred. Therefore, when the SNR of the received signal at the relay station is too low, as explained in Page 21, Lines 30-36 and in Page 22, Lines 1-17, with approximated channel information, the relay signal is transmitted by using the transmission filter and overcome the channel estimation error. Based on this observation, to determine whether the relay signal is arrived in the first time length, the control station always check the SNR of the received signal at the relay station.)determine that the relay of the first signal by the first relay station is executed in a case where it is determined that the relay signal of the first signal from the first relay station is able to arrive at the reception station within the first time length from the head of the slot; and determine that the relay the first signal by the first relay station is not executed in a case where it is determined that the relay signal of the first signal from the first relay station is not able to arrive at the reception station within the first time length from the head of the slot. (Ota teaches that as described in the above, the control station checks if the SNR of the received signal at the relay station is too low to estimate the channel information and based on this, the control station determines either to perform the channel estimation or to use the approximation of the channel information to compensate the delay time using filtering. Instead of determination of the claim condition, based on the approximation or estimation of channel information, the relay signal is always arrived in the first time length, unless the delay time between the relay station and the reception station is not greater than the first time length.)
Regarding claim 6, Ota teaches the features defined in the claim 5, -refer to the indicated claim for reference(s).
Ota further teaches that wherein the controller is configured to determine whether or not the relay signal of the first signal from the first relay station arrives at the reception station within the first time length from the head of the slot by determining whether or not a total time length of a propagation delay between the transmission station and the first relay station, a delay spread between the transmission station and the first relay station, a processing delay at the first relay station, and the propagation delay between the first relay station and the reception station is equal to or less than the first time length (Ota, in Fig. 20 and 25 teaches that based on Fig 20 and 25 and the channel estimation and in-phase synthesis method described in the above, at the transmitter of the relay station, the delay time can be defined as the sum of the delay time between the transmitter and the relay station and the signal processing delay of the relay station and further the delay time between the transmitter and the relay station can be defined as the sum of the propagation delay and the delay spread from the channel information estimated using two-wave model mentioned in the above. Thus, the total delay time between the transmitter and receiver can be defined as the sum of the delay time between the transmitter and the relay station (can be compensated by the transmitter weight of the relay station), the signal processing delay in the relay station, and the delay time between the relay station and the receiver (it might be compensated by the reception filter (weights) based on the estimated channel information). Therefore, if this total delay time is less than and equal to the first time length, the relay signal is arrived in the first time length.)
Regarding claim 7, Ota teaches the features defined in the claim 1, -refer to the indicated claim for reference(s).
Ota further teaches that further comprising a control device configured to manage a radio line, wherein the control device is configured to acquire the first time length on a basis of radio propagation characteristics between the transmission station and the reception station and respective radio propagation characteristics between the one or more relay stations and the reception station and notify the one or more relay stations of the first time length (Ota, in Page 24, Lines 22-37, in Page 25, and in Page 26, Lines 1-6, teaches that as described in Page 25, Lines 17-32, the channel information between the transmission station and relay stations and the channel information between the relay station and the reception station is acquired, by the control station, using two-wave model and based on this information, the delay time between a transmitter and relay stations and the delay time between relay stations and the receiver can be obtained by control station. In addition, since the relay station can be measured the signal processing delay time and it can be included into the channel information between the relay station and the receiver, it can be included into the delay time estimated based on the channel information between the relay station and the receiver. Based on this observation, the control station is configured to acquire the first time length based on the estimated delay times mentioned in the above with the channel information (radio propagation characteristics) between the transmitter and relay stations and the channel information between relay stations and the receiver.)
Regarding claim 8, Ota teaches the features defined in the claim 7, -refer to the indicated claim for reference(s).
Ota further teaches that wherein the control device is configured to acquire the first time length by summing a propagation delay between the transmission station and the reception station, a delay spread between the transmission station and the reception station, and a delay occurring by relay by one relay station among the one or more relay stations. (Ota, in Page 24, Lines 22-37, in Page 25, and in Page 26, Lines 1-6, teaches that as described in Page 25, Lines 17-32, the channel information between the transmission station and relay stations and the channel information between the relay station and the reception station is acquired, by the control station, using two-wave model and based on this information, the delay time between a transmitter and relay stations and the delay time between relay stations and the receiver can be obtained by control station. In addition, since the relay station can be measured the signal processing delay time and it can be included into the channel information between the relay station and the receiver, it can be included into the delay time estimated based on the channel information between the relay station and the receiver. Since the delay time can be defined as the propagation delay plus the delay spread, the first time length can be obtained by summing up the delay times mentioned above. Note that the delay occurring by relay by one relay station among the one or more relay stations can be considered as the signal processing delay of each relay station mentioned above. Based on this observation, the control station is configured to acquire the first time length by summing up the delay times (propagation delay plus delay spread) estimated by channel information mentioned in the above.)
Regarding claim 9, Ota teaches that comprising: acquiring, for at least a first relay station among one or more relay stations that relay a first signal from a transmission station to a reception station without demodulating or decoding the first signal, a first delay time and a first phase rotation amount to be provided to the first signal in relay by the first relay station on a basis of radio propagation characteristics between the transmission station and the first relay station and radio propagation characteristics between the reception station and the first relay station (Ota, in Fig. 1 and in Page 23, Lines 16-37 and in Page 24, Lines 1-8, teaches that in Fig. 1, if the signals transmitted from the control station 2 (it can be a controller and a transmitter station) can be received by the wireless modules (relay stations) 3-1 to 3-6 at almost the same time and the signals received by the wireless modules are transmitted immediately, synchronization is achieved as a result. However, in reality, if the path length difference is known, the timing is adjusted by adjusting the delay time by the time obtained by dividing the path length difference by the speed of light. When the distance between the control station 2 and the wireless modules 3-1 to 3-6 is known and the control station 2 and the wireless modules 3-1 to 3-6 are connected by a wireless line, it is possible to grasp the propagation delay, and the same delay time can be adjusted. In addition to adjusting the delay time by adjusting the timing of actual transmission or reception processing back and forth, if the time to be adjusted, that is, the timing error is known by measurement or the like. It is also possible to estimate how much the amount of rotation of the complex phase of the wireless signal in the wireless communication system changes due to the time difference, and to cope with the correction process by canceling the amount of rotation. In this case, the correction means that the transmission weight or the reception weight is corrected/changed to a value considering the influence of the timing error. Namely, in order to perform the in-phase synthesis, the transmission weight and the reception weight may be corrected and changed based on relative values such as path difference length and timing error. As described in Fig. 2 and in Page 24, Lines 22-37, in Page 25, and in Page 26, Lines 1-6, to perform in-phase synthesis, the channel characteristics is provided by two-wave model (since it represents propagation delay and delay spread corresponding to the channel and can be considered as radio propagation characteristics) and two-way model is estimated by the method described in Page 25, Lines 17-32. For in-phase synthesis, based on this method, the channel characteristic between control station and wireless modules and the channel characteristics between wireless modules and reception station are acquired for the transmission weight (transmission filter) or the reception weight (reception filter), respectively. Based on the above, control station provides the delay time and phase rotation amount can be estimated and applied to the relay signal (the first signal) for the correction through transmission filtering and reception filtering.) so that one or more relay signals of the first signal relayed by the one or more relay stations arrive at the reception station at the same time and in the same phase after a first time length from a head of a slot in a radio frame which is synchronous among the transmission station, the reception station, and the one or more relay stations and in which the first signal is transmitted; and causing the first relay station to provide the first delay time and the first phase rotation amount to the first signal. (Ota, in Fig. 20 and in Page 3, Lines 15-32, teach that In FIG. 20, 101 is a transmitting station, 102-1 to 102-4 are relay stations, and 103 is a receiving station. Here, a form of a wireless relay system is shown, and it is assumed that there are a total of N relay stations 102-1 to 102-4. By using coherent transmission system and in-phase synthesis method described in the above, first, the transmitting station 101 once transmits a wireless packet addressed to the receiving station 103 to the relay stations 102-1 to 102-4. The relay stations 102-1 to 102-4 perform various received signal processing on the received signals, and reproduce (restore) the wireless packets transmitted by the transmitting station 101. Next, each relay station 102-1 to 102-4 transmits the reproduced same wireless packet to the receiving station 103 at the same time. At this time, a signal transmitted from each relay station is received by the receiving station 103. The phase of the transmission signal is adjusted so that the signals are received at the same phase. The receiving station 103 synthesizes and receives all the signals from these relay stations 102-1 to 102-4. Based on the coherent transmission system and in-phase synthesis technique, the delay time and phase rotation amount of relay signals are adjusted and applied to the relay signals based on the transmission filter (transmission weights) and the reception filter (reception weights) and it determines the first time length and maintains the synchronous relationship of a transmission station, relay stations, and a reception station.)
Regarding claim 10, Ota teaches that a relay station comprising: a controller configured to acquire, in non-regenerative relay of relaying a first signal from a transmission station to a reception station without demodulating or decoding the first signal, a first delay time on a basis of radio propagation characteristics between the relay station and the reception station; acquire a first phase rotation amount that cancels a phase rotation amount to be applied to the first signal by the relay; (Ota, in Page 2, Lines 28-36 and in Page 3, Lines 1-13, teaches that due to a demand for lower power consumption of infrastructure including wireless communication, coherent transmission with a plurality of relay stations interposed is effective. Coherent transmission does not depend on whether the form of the relay is non-regenerative relay (without decoding or demodulation) or regenerative relay (with decoding, demodulation, or both) but it is important that each signal to transmit is synthesized in the same phase on the receiving side. Thus, although this art is described based on regenerative relay, the method can be applied to non-regenerative relay, too. For the wireless relay system, when a plurality of relay stations is connected to one base station, the base station and the relay station corresponds to the control station and the antenna of the distributed antenna system, respectively. Ota, in Fig. 1 and in Page 23, Lines 16-37 and in Page 24, Lines 1-8, teaches that in Fig. 1, if the signals transmitted from the control station 2 (it can be a controller and a transmitter station) can be received by the wireless modules (relay stations) 3-1 to 3-6 at almost the same time and the signals received by the wireless modules are transmitted immediately, synchronization is achieved as a result. However, in reality, if the path length difference is known, the timing is adjusted by adjusting the delay time by the time obtained by dividing the path length difference by the speed of light. When the distance between the control station 2 and the wireless modules 3-1 to 3-6 is known and the control station 2 and the wireless modules 3-1 to 3-6 are connected by a wireless line, it is possible to grasp the propagation delay, and the same delay time can be adjusted. In addition to adjusting the delay time by adjusting the timing of actual transmission or reception processing back and forth, if the time to be adjusted, that is, the timing error is known by measurement or the like. It is also possible to estimate how much the amount of rotation of the complex phase of the wireless signal in the wireless communication system changes due to the time difference, and to cope with the correction process by canceling the amount of rotation. In this case, the correction means that the transmission weight or the reception weight is corrected/changed to a value considering the influence of the timing error. Namely, in order to perform the in-phase synthesis, the transmission weight and the reception weight may be corrected and changed based on relative values such as path difference length and timing error. As described in Fig. 2 and in Page 24, Lines 22-37, in Page 25, and in Page 26, Lines 1-6, to perform in-phase synthesis, the channel characteristics is provided by two-wave model (since it represents propagation delay and delay spread corresponding to the channel and can be considered as radio propagation characteristics) and two-way model is estimated by the method described in Page 25, Lines 17-32. For in-phase synthesis, based on this method, the channel characteristic between control station and wireless modules and the channel characteristics between wireless modules and reception station are acquired for the transmission weight (transmission filter) or the reception weight (reception filter), respectively. Based on the above, control station provides the delay time and phase rotation amount can be estimated and applied to the relay signal (the first signal) for the correction through transmission filtering and reception filtering.) so that a relay signal of a first signal arrives at the reception station after a first time length from a head of a slot in a radio frame which is synchronous among the transmission station, the reception station, and one or more relay stations and in which the first signal is transmitted, and a radio processing unit configured to provide the first delay time and the first phase rotation amount to the first signal in the non-regenerative relay of the first signal. (Ota, in Fig. 20 and in Page 3, Lines 15-32, teach that In FIG. 20, 101 is a transmitting station, 102-1 to 102-4 are relay stations, and 103 is a receiving station. Here, a form of a wireless relay system is shown, and it is assumed that there are a total of N relay stations 102-1 to 102-4. By using coherent transmission system and in-phase synthesis method described in the above, first, the transmitting station 101 once transmits a wireless packet addressed to the receiving station 103 to the relay stations 102-1 to 102-4. The relay stations 102-1 to 102-4 perform various received signal processing on the received signals, and reproduce (restore) the wireless packets transmitted by the transmitting station 101. Next, each relay station 102-1 to 102-4 transmits the reproduced same wireless packet to the receiving station 103 at the same time. At this time, a signal transmitted from each relay station is received by the receiving station 103. The phase of the transmission signal is adjusted so that the signals are received at the same phase. The receiving station 103 synthesizes and receives all the signals from these relay stations 102-1 to 102-4. Based on the coherent transmission system and in-phase synthesis technique, the delay time and phase rotation amount of relay signals are adjusted and applied to the relay signals based on the transmission filter (transmission weights) and the reception filter (reception weights) and it determines the first time length and maintains the synchronous relationship of a transmission station, relay stations, and a reception station.)
Regarding claim 11, Ota teaches the features defined in the claim 10, -refer to the indicated claim for reference(s).
Ota further teaches that wherein the radio processing unit includes a first filter configured to perform filtering to suppress interference between a signal received from the transmission station and the signal to be transmitted to the reception station, the interference occurring in the radio processing unit, and the first filter is configured to provide the first delay time to the first signal by the filtering and provide the first phase rotation amount to the first signal after the filtering (Ota, in Fig. 25 and in Page 11, 31-36 and in Page 12, Lines 1-23, teaches that in Fig. 25, each analog signal is multiplied by signals input from local oscillators 175-1 to 175-3 by mixers 168-1 to 168-3, and is up-converted to a radio frequency signal. Since the signal here includes a signal also in the frequency component outside the band of the channel to be transmitted, the out-of-band component (it is a kind of interference between a signal received from transmission station and the signal to be transmitted to the reception station) is removed by the filters 169-1 to 169-3 (suppressing interference), and this is converted to the high power amplifiers 170-1 to 170-3, the signal is amplified and transmitted from the antennas 171-1 to 171-3. The signals transmitted from the wireless modules 176-1 to 176-3 are basically the same signals except that they are multiplied by different transmission weights (transmission filter). Phase synthesis can be realized (as shown in the above, this procedure includes adjusting delay time and phase rotation amount). The transmission weights multiplied by the transmission signal processing circuits 166-1 to 166-3 are separately acquired by the channel information acquisition circuits 172-1 to 172-3, and the channel information storage circuit 173 is updated sequentially. At the time of signal transmission, transmission weight calculation circuits 174-1 to 174-3 read channel information from channel information storage circuits 173-1 to 173-3, calculate transmission weights based on the information, and use these as transmission signals. Applying transmission weights (filtering) compensates the delay time and the phase rotation amount in in-phase synthesis technique and equalizes the relay signal (the first signal). Therefore, the filtering by the filters 169-1 to 169-3 and transmission filters 174-1 to 174-3 in relay station suppress interference (out of band interference and the inter-symbol interference due to delay time and phase rotation amount) of the input signal of the relay station and further, thru the transmission filtering, the delay time compensation and phase rotation amount correction is applied to the relay input signal (the first signal).)
Regarding claim 12, Ota teaches the features defined in the claim 10, -refer to the indicated claim for reference(s).
Ota further teaches that wherein the controller is configured to acquire the first delay time so that the relay signal of the first signal is transmitted from the radio processing unit after a second time length from the head of the slot, the second time length being obtained by subtracting a propagation delay between the relay station and the reception station from the first time length (Ota, in Fig. 1 and 2 and in Page 23, Lines 16-37, in Page 24, Lines 1-8, in Page 24, Lines 22-37, in Page 25, and in Page 26, Lines 1-6, teaches that as described in Page 25, Lines 17-32, the channel information between a transmission station and the relay station is acquired, by the control station, using two-wave model and based on this information, the delay time information and phase rotation amount of the relay signal are estimated at the relay station. By using in-phase synthesis with transmission filter (weighting), the delay time and phase rotation amount are compensated or corrected. Then, ideally, the delay time between the relay station and the reception station becomes a delay of the processing time of relay station and a propagation delay between the relay station and the reception station. Therefore, if the processing time of the relay station is measured or known and further the relay station compensates this processing delay, the second time length can be zero and the relay station can send the relay signal without considering the second time length. Then, the condition of the claim can be satisfied by the control station.)
Regarding claim 13, Ota teaches the features defined in the claim 10, -refer to the indicated claim for reference(s).
Ota further teaches that wherein the radio processing unit includes a transmitter and a receiver to be connected to an antenna, and (Ota, in Fig. 25, teaches that Fig. 25 shows that a relay station is connected with a transmit station and a reception station with antenna(s), respectively.) the controller is configured to acquire, as the first phase rotation amount, a value obtained by subtracting a phase rotation amount to be applied at the transmitter, a phase rotation amount to be applied on a propagation path from the transmission station to the relay station, and a phase rotation amount to be applied on a propagation path from the relay station to the reception station from a phase rotation amount to be applied at the receiver (Ota, in Fig. 2 and in Page 24, Lines 22-37, in Page 25, and in Page 26, Lines 1-6, teaches that as described in Page 25, Lines 17-32, the channel information between a transmission station and the relay station is acquired, by the control station, using two-wave model and based on this information, the delay time information and phase rotation amount between transmitter and the relay station are estimated at the relay station. This phase rotation amount can be considered as the sum of a phase rotation amount at the transmitter and a phase rotation amount to be applied on a propagation path from the transmission station to the relay station. In the relay station, as shown in the above, by the filtering, this phase rotation amount is compensated or corrected at the relay station. Then, at the reception station, by using the same method, the channel information (propagation path information) between the relay station and reception is estimated and based on this information, the phase rotation amount between the relay and the reception station is estimated or measured by the control station. Since the phase rotation amount measured in the relay station is already corrected or compensated (ideally, this amount is zero), the measured phase rotation amount between a relay station and the reception station becomes the phase rotation amount to be applied on a propagation path from the first relay station to the reception station and also, it becomes the first phase rotation amount.)
Regarding claim 14, Ota teaches the features defined in the claim 10, -refer to the indicated claim for reference(s).
Ota further teaches that wherein the controller is configured to determine whether or not the relay signal of the first signal transmitted from the radio processing unit is able to arrive at the reception station within a first time length from the head of the slot on a basis of a propagation delay between the relay station and the reception station, (Ota, in Fig. 1 and 2 and in Page 23, Lines 16-37, in Page 24, Lines 1-8, in Page 24, Lines 22-37, in Page 25, and in Page 26, Lines 1-6, teaches that as described in Page 25, Lines 17-32, the channel information between a transmission station and the relay station is acquired, by the control station, using two-wave model and based on this information, the delay time information and phase rotation amount between transmitter and the relay station are estimated at the relay station. Then, by in-phase synthesis technique and transmission filtering, the delay time between the transmitter and the relay station is compensated or corrected. Unless severe error occurred in channel information or the processing time of the relay station is too big, the relay signal is always arrived in the first time length due to compensation, if the delay time between the relay station and the reception station is not greater than the first time length. However, if at the relay station, the SNR of the received signal is too low (causing the severe error in the channel estimation), then, it might be occurred. Therefore, when the SNR of the received signal at the relay station is too low, as explained in Page 21, Lines 30-36 and in Page 22, Lines 1-17, with approximated channel information, the relay signal is transmitted by using the transmission filter and overcome the channel estimation error. Based on this observation, to determine whether the relay signal is arrived in the first time length, the control station always check the SNR of the received signal at the relay station.) determine to relay the first signal in a case where it is determined that the relay signal of the first signal is able to arrive at the reception station within the first time length from the head of the slot, and determine not to relay the first signal in a case where it is determined that the relay signal of the first signal is not able to arrive at the reception station within the first time length from the head of the slot (Ota teaches that as described in the above, the control station checks if the SNR of the received signal at the relay station is too low to estimate the channel information and based on this, the control station determines either to perform the channel estimation or to use the approximation of the channel information to compensate the delay time using filtering. Instead of determination of the claim condition, based on the approximation or estimation of channel information, the relay signal is always arrived in the first time length, unless the delay time between the relay station and the reception station is not greater than the first time length.)
Regarding claim 15, Ota teaches the features defined in the claim 14, -refer to the indicated claim for reference(s).
Ota further teaches that wherein the controller is configured to determine whether or not the relay signal of the first signal is able to arrive at the reception station within the first time length from the head of the slot by determining whether or not a total time length of a propagation delay between the transmission station and the relay station, a delay spread between the transmission station and the relay station, a processing delay at the radio processing unit, and the propagation delay between the relay station and the reception station is equal to or less than the first time length (Ota, in Fig. 20 and 25 teaches that based on Fig 20 and 25 and the channel estimation and in-phase synthesis method described in the above, at the transmitter of the relay station, the delay time can be defined as the sum of the delay time between the transmitter and the relay station and the signal processing delay of the relay station and further the delay time between the transmitter and the relay station can be defined as the sum of the propagation delay and the delay spread from the channel information estimated using two-wave model mentioned in the above. Thus, the total delay time between the transmitter and receiver can be defined as the sum of the delay time between the transmitter and the relay station (can be compensated by the transmitter weight of the relay station), the signal processing delay in the relay station, and the delay time between the relay station and the receiver (it might be compensated by the reception filter (weights) based on the estimated channel information). Therefore, if this total delay time is less than and equal to the first time length, the relay signal is arrived in the first time length.)
Regarding claim 16, Ota teaches the features defined in the claim 10, -refer to the indicated claim for reference(s).
Ota further teaches that wherein the controller is configured to receive the first time length acquired on a basis of radio propagation characteristics between the transmission station and the reception station and respective radio propagation characteristics between the one or more relay stations and the reception station, from a control device that manages a radio line (Ota, in Page 24, Lines 22-37, in Page 25, and in Page 26, Lines 1-6, teaches that as described in Page 25, Lines 17-32, the channel information between the transmission station and relay stations and the channel information between the relay station and the reception station is acquired, by the control station, using two-wave model and based on this information, the delay time between a transmitter and relay stations and the delay time between relay stations and the receiver can be obtained by control station. In addition, since the relay station can be measured the signal processing delay time and it can be included into the channel information between the relay station and the receiver, it can be included into the delay time estimated based on the channel information between the relay station and the receiver. Based on this observation, the control station is configured to acquire the first time length based on the estimated delay times mentioned in the above with the channel information (radio propagation characteristics) between the transmitter and relay stations and the channel information between relay stations and the receiver.)
Regarding claim 17, Ota teaches the features defined in the claim 16, -refer to the indicated claim for reference(s).
Ota further teaches that wherein the first time length is acquired by summing a propagation delay between the transmission station and the reception station, a delay spread between the transmission station and the reception station, and a delay occurring by relay by one relay station among the one or more relay stations. (Ota, in Page 24, Lines 22-37, in Page 25, and in Page 26, Lines 1-6, teaches that as described in Page 25, Lines 17-32, the channel information between the transmission station and relay stations and the channel information between the relay station and the reception station is acquired, by the control station, using two-wave model and based on this information, the delay time between a transmitter and relay stations and the delay time between relay stations and the receiver can be obtained by control station. In addition, since the relay station can be measured the signal processing delay time and it can be included into the channel information between the relay station and the receiver, it can be included into the delay time estimated based on the channel information between the relay station and the receiver. Since the delay time can be defined as the propagation delay plus the delay spread, the first time length can be obtained by summing up the delay times mentioned above. Note that the delay occurring by relay by one relay station among the one or more relay stations can be considered as the signal processing delay of each relay station mentioned above. Based on this observation, the control station is configured to acquire the first time length by summing up the delay times (propagation delay plus delay spread) estimated by channel information mentioned in the above.)
Regarding claim 18, Ota teaches that a control device comprising: a controller configured to acquire a first time length on a basis of radio propagation characteristics between a transmission station and a reception station and respective radio propagation characteristics between one or more relay stations and the reception station, (Ota, in Page 24, Lines 22-37, in Page 25, and in Page 26, Lines 1-6, teaches that as described in Page 25, Lines 17-32, the channel information between the transmission station and relay stations and the channel information between the relay station and the reception station is acquired, by the control station, using two-wave model and based on this information, the delay time between a transmitter and relay stations and the delay time between relay stations and the receiver can be obtained by control station. In addition, since the relay station can be measured the signal processing delay time and it can be included into the channel information between the relay station and the receiver, it can be included into the delay time estimated based on the channel information between the relay station and the receiver. Based on this observation, the control station is configured to acquire the first time length based on the estimated delay times mentioned in the above with the channel information (radio propagation characteristics) between the transmitter and relay stations and the channel information between relay stations and the receiver.) the one or more relay stations being configured to relay a first signal from the transmission station to the reception station without demodulating or decoding the first signal, (Ota, in Page 2, Lines 28-36 and in Page 3, Lines 1-13, teaches that due to a demand for lower power consumption of infrastructure including wireless communication, coherent transmission with a plurality of relay stations interposed is effective. Coherent transmission does not depend on whether the form of the relay is non-regenerative relay (without decoding or demodulation) or regenerative relay (with decoding, demodulation, or both) but it is important that each signal to transmit is synthesized in the same phase on the receiving side. Thus, although this art is described based on regenerative relay, the method can be applied to non-regenerative relay, too. For the wireless relay system, when a plurality of relay stations is connected to one base station, the base station and the relay station corresponds to the control station and the antenna of the distributed antenna system, respectively.) the one or more relay stations providing a first delay time and a first phase rotation amount to the first signal (Ota, in Fig. 1 and in Page 23, Lines 16-37 and in Page 24, Lines 1-8, teaches that in Fig. 1, if the signals transmitted from the control station 2 (it can be a controller and a transmitter station) can be received by the wireless modules (relay stations) 3-1 to 3-6 at almost the same time and the signals received by the wireless modules are transmitted immediately, synchronization is achieved as a result. However, in reality, if the path length difference is known, the timing is adjusted by adjusting the delay time by the time obtained by dividing the path length difference by the speed of light. When the distance between the control station 2 and the wireless modules 3-1 to 3-6 is known and the control station 2 and the wireless modules 3-1 to 3-6 are connected by a wireless line, it is possible to grasp the propagation delay, and the same delay time can be adjusted. In addition to adjusting the delay time by adjusting the timing of actual transmission or reception processing back and forth, if the time to be adjusted, that is, the timing error is known by measurement or the like. It is also possible to estimate how much the amount of rotation of the complex phase of the wireless signal in the wireless communication system changes due to the time difference, and to cope with the correction process by canceling the amount of rotation. In this case, the correction means that the transmission weight or the reception weight is corrected/changed to a value considering the influence of the timing error. Namely, in order to perform the in-phase synthesis, the transmission weight and the reception weight may be corrected and changed based on relative values such as path difference length and timing error. As described in Fig. 2 and in Page 24, Lines 22-37, in Page 25, and in Page 26, Lines 1-6, to perform in-phase synthesis, the channel characteristics is provided by two-wave model (since it represents propagation delay and delay spread corresponding to the channel and can be considered as radio propagation characteristics) and two-way model is estimated by the method described in Page 25, Lines 17-32. For in-phase synthesis, based on this method, the channel characteristic between control station and wireless modules and the channel characteristics between wireless modules and reception station are acquired for the transmission weight (transmission filter) or the reception weight (reception filter), respectively. Based on the above, control station provides the delay time and phase rotation amount can be estimated and applied to the relay signal (the first signal) for the correction through transmission filtering and reception filtering.) so that relay signals of the first signal arrive at the reception station at the same time and in the same phase after the first time length from a head of a slot in a radio frame which is synchronous among the transmission station, the reception station, and the one or more relay stations and in which the first signal is transmitted (Ota, in Fig. 20 and in Page 3, Lines 15-32, teach that In FIG. 20, 101 is a transmitting station, 102-1 to 102-4 are relay stations, and 103 is a receiving station. Here, a form of a wireless relay system is shown, and it is assumed that there are a total of N relay stations 102-1 to 102-4. By using coherent transmission system and in-phase synthesis method described in the above, first, the transmitting station 101 once transmits a wireless packet addressed to the receiving station 103 to the relay stations 102-1 to 102-4. The relay stations 102-1 to 102-4 perform various received signal processing on the received signals, and reproduce (restore) the wireless packets transmitted by the transmitting station 101. Next, each relay station 102-1 to 102-4 transmits the reproduced same wireless packet to the receiving station 103 at the same time. At this time, a signal transmitted from each relay station is received by the receiving station 103. The phase of the transmission signal is adjusted so that the signals are received at the same phase. The receiving station 103 synthesizes and receives all the signals from these relay stations 102-1 to 102-4. Based on the coherent transmission system and in-phase synthesis technique, the delay time and phase rotation amount of relay signals are adjusted and applied to the relay signals based on the transmission filter (transmission weights) and the reception filter (reception weights) and it determines the first time length and maintains the synchronous relationship of a transmission station, relay stations, and a reception station.)
Regarding claim 19, Ota teaches the features defined in the claim 18, -refer to the indicated claim for reference(s).
Ota further teaches that wherein the controller is configured to acquire the first time length by summing a propagation delay between the transmission station and the reception station, a delay spread between the transmission station and the reception station, and a delay occurring by relay by one relay station among the one or more relay stations. (Ota, in Page 24, Lines 22-37, in Page 25, and in Page 26, Lines 1-6, teaches that as described in Page 25, Lines 17-32, the channel information between the transmission station and relay stations and the channel information between the relay station and the reception station is acquired, by the control station, using two-wave model and based on this information, the delay time between a transmitter and relay stations and the delay time between relay stations and the receiver can be obtained by control station. In addition, since the relay station can be measured the signal processing delay time and it can be included into the channel information between the relay station and the receiver, it can be included into the delay time estimated based on the channel information between the relay station and the receiver. Since the delay time can be defined as the propagation delay plus the delay spread, the first time length can be obtained by summing up the delay times mentioned above. Note that the delay occurring by relay by one relay station among the one or more relay stations can be considered as the signal processing delay of each relay station mentioned above. Based on this observation, the control station is configured to acquire the first time length by summing up the delay times (propagation delay plus delay spread) estimated by channel information mentioned in the above.)
Regarding claim 20, Ota teaches the features defined in the claim 18, -refer to the indicated claim for reference(s).
Ota further teaches that wherein the controller is configured to acquire, for at least a first relay station among the one or more relay stations, the first delay time and the first phase rotation amount to be provided to the first signal in relay by the first relay station on a basis of radio propagation characteristics between the transmission station and the first relay station and radio propagation characteristics between the reception station and the first relay station, and notify the first relay station of the first delay time and the first phase rotation amount (Ota, in Fig. 1 and in Page 23, Lines 16-37 and in Page 24, Lines 1-8, teaches that in Fig. 1, if the signals transmitted from the control station 2 (it can be a controller and a transmitter station) can be received by the wireless modules (relay stations) 3-1 to 3-6 at almost the same time and the signals received by the wireless modules are transmitted immediately, synchronization is achieved as a result. However, in reality, if the path length difference is known, the timing is adjusted by adjusting the delay time by the time obtained by dividing the path length difference by the speed of light. When the distance between the control station 2 and the wireless modules 3-1 to 3-6 is known and the control station 2 and the wireless modules 3-1 to 3-6 are connected by a wireless line, it is possible to grasp the propagation delay, and the same delay time can be adjusted. In addition to adjusting the delay time by adjusting the timing of actual transmission or reception processing back and forth, if the time to be adjusted, that is, the timing error is known by measurement or the like. It is also possible to estimate how much the amount of rotation of the complex phase of the wireless signal in the wireless communication system changes due to the time difference, and to cope with the correction process by canceling the amount of rotation. In this case, the correction means that the transmission weight or the reception weight is corrected/changed to a value considering the influence of the timing error. Namely, in order to perform the in-phase synthesis, the transmission weight and the reception weight may be corrected and changed based on relative values such as path difference length and timing error. As described in Fig. 2 and in Page 24, Lines 22-37, in Page 25, and in Page 26, Lines 1-6, to perform in-phase synthesis, the channel characteristics is provided by two-wave model (since it represents propagation delay and delay spread corresponding to the channel and can be considered as radio propagation characteristics) and two-way model is estimated by the method described in Page 25, Lines 17-32. For in-phase synthesis, based on this method, the channel characteristic between control station and wireless modules and the channel characteristics between wireless modules and reception station are acquired for the transmission weight (transmission filter) or the reception weight (reception filter), respectively. Based on the above, control station provides the delay time and phase rotation amount can be estimated and applied to the relay signal (the first signal) for the correction through transmission filtering and reception filtering.)
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Takahashi, Yasuo et. al. (JPPub. JP4374023 B2, hereinafter “Yasuo”) which explains about delay time, phase rotation amount, and channel estimation with relay communication.
Yoshimoto Takashi et. al. (JPPub. JP2011244404 A, hereinafter “Takashi”) which explains about delay time, filtering, and channel information for relay communication.
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/JAEYOUNG KWAK/Examiner, Art Unit 2472
/KEVIN T BATES/Supervisory Patent Examiner, Art Unit 2472