WO2012126429A2 - 一种频偏校正方法及装置 - Google Patents
一种频偏校正方法及装置 Download PDFInfo
- Publication number
- WO2012126429A2 WO2012126429A2 PCT/CN2012/075936 CN2012075936W WO2012126429A2 WO 2012126429 A2 WO2012126429 A2 WO 2012126429A2 CN 2012075936 W CN2012075936 W CN 2012075936W WO 2012126429 A2 WO2012126429 A2 WO 2012126429A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- frequency offset
- estimated frequency
- estimated
- signal
- offset values
- Prior art date
Links
- 238000000034 method Methods 0.000 title claims abstract description 73
- 238000012937 correction Methods 0.000 claims description 146
- 238000012545 processing Methods 0.000 claims description 60
- 238000001914 filtration Methods 0.000 claims description 20
- 238000007781 pre-processing Methods 0.000 claims description 13
- 230000015572 biosynthetic process Effects 0.000 claims description 9
- 238000003786 synthesis reaction Methods 0.000 claims description 9
- 108010001267 Protein Subunits Proteins 0.000 claims description 8
- 238000004590 computer program Methods 0.000 claims description 7
- 238000000605 extraction Methods 0.000 claims description 2
- 230000010354 integration Effects 0.000 claims description 2
- 230000005540 biological transmission Effects 0.000 description 54
- 239000011159 matrix material Substances 0.000 description 26
- 238000004364 calculation method Methods 0.000 description 8
- 238000010586 diagram Methods 0.000 description 8
- 238000013507 mapping Methods 0.000 description 4
- 238000004891 communication Methods 0.000 description 3
- 238000010276 construction Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 230000003044 adaptive effect Effects 0.000 description 2
- 238000004422 calculation algorithm Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 230000006735 deficit Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000013178 mathematical model Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
- 230000026676 system process Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/0413—MIMO systems
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
- H04L25/03891—Spatial equalizers
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/0014—Carrier regulation
- H04L2027/0024—Carrier regulation at the receiver end
- H04L2027/0026—Correction of carrier offset
- H04L2027/003—Correction of carrier offset at baseband only
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/0014—Carrier regulation
- H04L2027/0024—Carrier regulation at the receiver end
- H04L2027/0026—Correction of carrier offset
- H04L2027/0038—Correction of carrier offset using an equaliser
- H04L2027/0042—Correction of carrier offset using an equaliser the equaliser providing the offset correction per se
Definitions
- the present invention relates to the field of communications technologies, and in particular, to a frequency offset correction method and apparatus for use in a distributed MIM0 (Multiple Input Multiple Output) system.
- MIM0 Multiple Input Multiple Output
- MIM0 technology is an effective means to improve the spectrum efficiency of communication systems by using multi-antenna technology, and has extremely high application value in wireless and microwave communication.
- different antenna pairs form a plurality of different subchannels.
- the receiving end can use the corresponding algorithm to decode and distinguish data on different transmitting antennas, thereby achieving The effect of simultaneously transmitting multiple channels of information on the same frequency band doubles the spectrum efficiency.
- each 0DU includes L0 (Local Oscillator). Due to the difference of L0 devices in each 0DU, the multiple baseband signals received by one antenna at the receiving end exhibit different CFOs (Carrier Frequency Offset, carrier frequency offset, referred to as frequency offset), making it difficult for the decoding system at the receiving end to converge to a stable state. In the decoding state, the decoding performance is seriously deteriorated.
- L0 Local Oscillator
- a specially constructed known sequence such as a CAZAC (Const Amplitude Zero Auto Corelation) sequence
- CAZAC Const Amplitude Zero Auto Corelation
- the orthogonality of the sequence in time and space, the CF0 parameter of the distributed MIM0 system can be obtained through calculation, and the signal correction is implemented according to the CF0 parameter, thereby improving the decoding performance.
- the embodiment of the invention provides a frequency offset correction method and device.
- the technical solution is as follows:
- a frequency offset correction method in a distributed multiple input multiple output MIM0 system including: receiving n first signals, where n is a positive integer; Performing frequency offset correction processing on the n first signals to obtain n first correction signals;
- a frequency offset correction apparatus in a distributed multiple input multiple output MIM0 system including: a receiver, configured to receive n first signals, where n is a positive integer;
- a processor configured to perform frequency offset correction processing on the n first signal, to obtain n first correction signals
- an acquiring unit configured to acquire n n of space-time equalizers corresponding to the n first correction signals a center tap coefficient, a first output phase of the phase-locked loop phase detector corresponding to the n-channel first correction signal, and a second output phase of the phase-locked loop phase detector corresponding to the superimposed signal, wherein the superimposed signal is a signal obtained by superimposing the n first correction signals one by one;
- a first estimation acquiring unit configured to acquire n first estimated frequency offset values according to the n center tap coefficients and the n first output phases
- a second estimation acquiring unit configured to acquire a second estimated frequency offset value according to the second output phase
- a receiving correction unit configured to receive the n second signals, and perform frequency offset correction on the n second signals according to the n first estimated frequency offset values and the second estimated frequency offset values.
- the technical solution provided by the embodiment of the present invention has the following beneficial effects: obtaining n first estimates according to n center tap coefficients corresponding to the n first correction signals and n first output phases corresponding to the n first correction signals
- the frequency offset value that is, the estimated frequency offset value of the receiving end; the second estimated frequency offset value of the transmitting end is obtained according to the second output phase corresponding to the superposed signal; that is, the method for calculating the known sequence in the transmission data of the baseband signal is not needed.
- Estimating the frequency offset, but according to the transmission data of the baseband signal, that is, the first correction signal can obtain the respective estimated frequency offsets of the receiving end and the transmitting end, and then according to the estimated frequency offset of the receiving end and the transmitting end, the second received current path is second.
- the signal is frequency offset corrected to ensure efficient data transmission.
- the frequency offset is estimated according to the transmission data of the baseband signal, and the transmission process of the transmission data is continuous. Therefore, the method in this embodiment has a dynamic tracking characteristic; and the estimated frequency offset of the receiving end and the transmitting end is calculated. The process does not involve high-dimensional matrix calculation, which reduces the computational complexity.
- the frequency offset of the transmitting and receiving ends can be compensated at the receiving end. Compared with the prior art, the frequency offset of the transmitting end is performed at the transmitting end by means of feedback. For compensation, Reduce the complexity of the compensation system.
- FIG. 1 is a flowchart of an embodiment of a frequency offset correction method in a distributed MIM0 system according to Embodiment 1 of the present invention
- FIG. 2 is a frequency offset correction method in a distributed MIM0 system according to Embodiment 2 of the present invention
- FIG. 3 is a schematic flowchart of a first estimated frequency offset value according to Embodiment 2 of the present invention
- FIG. 4 is a schematic diagram of synthesizing a first estimated frequency offset value according to Embodiment 2 of the present invention.
- FIG. 5 is a flowchart of an embodiment of a frequency offset correction method in a distributed MIM0 system according to Embodiment 3 of the present invention
- FIG. 6 is a frequency offset correction apparatus in a distributed MIM0 system according to Embodiment 5 of the present invention
- FIG. 7 is a second schematic structural diagram of an embodiment of a frequency offset correction apparatus in a distributed MIM0 system according to Embodiment 5 of the present invention.
- FIG. 8 is a schematic diagram of signal processing of a microwave MIM0 system according to Embodiment 5 of the present invention. detailed description
- Equation (1) is the transmission system without CF0, as shown below:
- FIG. 1 is a flowchart of an embodiment of a frequency offset correction method in a distributed MIM0 system according to Embodiment 1 of the present invention
- the frequency offset correction method in the distributed MIM0 system includes:
- S101 Receive n first signals, where n is a positive integer.
- S102 perform frequency offset correction processing on the n first signals to obtain n first correction signals.
- S103 acquiring n center tap coefficients of the space-time equalizer corresponding to the n-channel first correction signal, and n first output phases and superpositions of the phase-locked loop phase detector corresponding to the n-channel first correction signal a second output phase of the phase-locked loop phase detector corresponding to the signal, wherein the superimposed signal is a signal obtained by superimposing the n-channel first correction signals one by one.
- S104 Acquire n first estimated frequency offset values according to the n center tap coefficients and the n first output phases.
- S105 Acquire a second estimated frequency offset value according to the second output phase.
- S106 Receive n second signals, perform frequency offset correction on the n second signals according to the n first estimated frequency offset values and the second estimated frequency offset values.
- n first estimated frequency offset values that is, estimates of the receiving end, are obtained according to n center tap coefficients corresponding to the n first correction signals and n first output phases corresponding to the n first correction signals.
- Frequency offset value The second output phase corresponding to the signal acquires the second estimated frequency offset value of the transmitting end; that is, the estimated frequency offset is not calculated by inserting a known sequence into the transmission data of the baseband signal, but is based on the transmission data of the baseband signal, that is,
- the first correction signal can obtain the estimated frequency offset of each of the receiving end and the transmitting end, and then perform frequency offset correction on the currently received n second signal according to the estimated frequency offset of the receiving end and the transmitting end, thereby ensuring effective data transmission.
- the frequency offset is estimated according to the transmission data of the baseband signal, and the transmission process of the transmission data is continuous. Therefore, the method in this embodiment has a dynamic tracking characteristic; and the estimated frequency offset of the receiving end and the transmitting end is calculated. The process does not involve high-dimensional matrix calculation, which reduces the computational complexity.
- the frequency offset of the transmitting and receiving ends can be compensated at the receiving end. Compared with the prior art, the frequency offset of the transmitting end is performed at the transmitting end by means of feedback. In terms of compensation, the complexity of the compensation system is reduced.
- FIG. 2 is a flowchart of an embodiment of a frequency offset correction method in a distributed MIM0 system according to Embodiment 2 of the present invention
- the frequency offset correction method in the distributed MIM0 system includes:
- S201 receiving an n-channel first baseband signal sent by the transmitting end, performing digital processing on the n-channel first baseband signal, and receiving the digitally processed n-channel first signal; and first, the n-channel according to the estimated frequency offset The signal is subjected to frequency offset correction to obtain n first correction signals.
- the receiving end when the receiving end first receives the first baseband signal sent by the transmitting end, the receiving end sequentially receives the first baseband by the baseband processing system, such as an IDU (InDoor Unit), after receiving the antenna and the 0DU. And performing signal-to-analog conversion and filtering on the first baseband signal to generate a first signal, where the first signal is a digital signal.
- the baseband processing system such as an IDU (InDoor Unit)
- Each of the n receiving branches of the receiving baseband processing system receives one of the first baseband signals, and each receiving branch processes the first baseband signal according to the foregoing process to generate an n-channel first signal; wherein, A signal includes CF0 at the receiving end and CF0 at the transmitting end.
- the receiving end When the receiving end first receives the first baseband signal sent by the transmitting end, the estimated frequency offset is 0; then the n first correcting signal obtained by performing frequency offset estimation on the n first signal according to the estimated frequency offset is still
- the n signal is the first signal; wherein the first correction signal also includes the CF0 of the receiving end and the CF0 of the transmitting end.
- S202 Acquire n center tap coefficients of the space-time equalizer corresponding to the n-channel first correction signal, and n first output phases and superimposed signals of the phase-locked loop phase detector corresponding to the n-channel first correction signal. a second output phase of the phase-locked loop phase detector, wherein the superimposed signal is a signal obtained by superimposing the n-channel first correction signals one by one.
- the baseband processing system of the receiving end obtains the n first correcting signal
- performing decoding processing of the MIM0 signal on the n first correcting signal specifically, the n first correcting signal may be used.
- Pass through The STE (Space Time Equalizer) and the phase-locked loop phase detector respectively perform space-time equalization processing and lock equalization processing to perform decoding, and obtain the decoded n-channel first correction signal, and then decode the decoded
- the n-channel first correction signal is subjected to decision synthesis processing to obtain a decoded single-channel signal.
- the space-time equalizer and the phase-locked loop phase detector will change with the transmission signal in the channel, and n is a positive integer.
- the n-channel first correction signal sequentially passes through the STE and the phase-locked loop phase detector, respectively acquiring n center tap coefficients of the STE on the signal channel corresponding to the n-channel first correction signal, and the n-channel first a second output phase of the phase-locked loop phase detector corresponding to the superimposed signal obtained by superimposing the n first phase of the phase-locked loop phase detector on the signal channel corresponding to the correction signal and the n-channel first correction signal being superposed one by one .
- the frequency offset will continuously change the gradient direction of the decision error to form a statistical offset. Since the adaptive STE will track the gradient direction of the error, the center tap coefficient of the STE can indicate the frequency.
- the direction of the bias, where the center tap coefficient of the STE of the branch channel reflects the CF0 information of different 0DUs at the receiving end.
- the phase of the phase-locked loop phase detector output will also accumulate in time according to the direction of the frequency offset, so the output phase of the phase-locked loop phase detector
- the frequency offset can be indicated, wherein the output phase of the phase-locked loop phase detector of the branch channel, that is, the first output phase reflects the CF0 information of different 0DUs at the receiving end; the output phase of the phase-locked loop phase detector of the superimposed channel, ie, The two output phases reflect the CF0 information of the decoded signal corresponding to the transmitting terminal 0DU.
- S203 Acquire n first estimated frequency offset values of the 0DUs on the n receiving branches according to the n center tap coefficients and the n first output phases, and acquire a second estimated frequency of the transmitting end according to the second output phase. Offset value.
- the information of the STE and the phase-locked loop is used to estimate CF0, that is, the center tap coefficient of the STE and the output phase of the phase-locked loop phase detector are used to estimate CF0, thereby achieving blind frequency offset estimation, without Depending on the calculation of the known sequence, the estimated frequency offset of each of the transmitting end and the receiving end can be obtained.
- FIG. 3 is a schematic flowchart of a first estimated frequency offset value according to Embodiment 2 of the present invention.
- the calculation process of the first estimated frequency offset value includes:
- S203a Acquire n first estimated frequency offsets of 0DUs on the receiving branch according to the n center tap coefficients.
- the instantaneous phase information of the n center tap coefficients are separately extracted to obtain n pieces of instantaneous phase information; respectively, the n pieces of instantaneous phase information are separately subjected to difference operations to obtain n first frequency information; respectively, for the n
- the first frequency information is subjected to clipping processing to obtain n pieces of first frequency information after clipping; respectively, performing low-pass filtering processing on the n first limited frequency information to obtain 0DUs of n receiving branches n first sub-estimation frequency offsets.
- S203b Acquire n second estimated frequency offsets of the 0DUs on the n receiving branches according to the n first output phases. Specifically, performing differential operations on the n first output phases to obtain n second frequency information; performing low-pass filtering processing on the n second frequency information to obtain 0DUs on the n receiving branches The n second sub-estimates the frequency offset.
- S203c performing gain control and superposition synthesis processing on the n first sub-estimation frequency offsets and the n second sub-estimation frequency offsets on the corresponding receiving branch 0DU, to obtain n pieces of the 0DUs on the n receiving branches An estimated frequency offset value.
- FIG. 4 is provided in Embodiment 2 of the present invention.
- the center tap coefficient and the first output phase of the STE both reflect the CF0 information of different 0DUs at the receiving end, the first sub-estimated frequency offset obtained by the center tap coefficient according to the STE, and the second sub-estimated frequency obtained according to the first output phase.
- the combination of the two methods of gain control such as gain can further improve the robustness of the estimation tracking.
- the process of obtaining the second estimated frequency offset value of the transmitting end according to the second output phase is similar to that of S203b, specifically: performing differential operation on the second output phase to obtain third frequency information;
- the three-frequency information is subjected to low-pass filtering processing to obtain a second estimated frequency offset value of the transmitting end.
- the baseband processing is required.
- the system judges whether the decoding operation in the decoding process of the MIM0 signal is a linear operation, in which the decoding operation normally satisfies linearity.
- the frequency offset compensation of the transmitting terminal 0DU can be switched to the decoding process, and the frequency offset compensation of the receiving terminal 0DU is completed, that is, the n first estimated frequency offsets of the 0DUs on the n receiving branches.
- the value is combined with the second estimated frequency offset value of the transmitting end to compensate for the frequency offset of the receiving end and the transmitting end.
- the first correction signal is the first signal after the frequency offset correction processing; in the embodiment of the present invention, the frequency offset estimation is performed on the first received signal, and then the second current reception is performed. The signal is compensated for frequency offset.
- preprocessing the n third estimated frequency offset values After obtaining the n third estimated frequency offset values, preprocessing the n third estimated frequency offset values to determine whether the preprocessed n third estimated frequency offset values converge, if yes And performing frequency offset correction on the n second signals according to the preprocessed n third estimated frequency offset values to obtain a frequency offsetless signal; if not, according to the preprocessed n thirds
- the estimated frequency offset value is respectively frequency offset corrected for the n second signals, and the first modified signal of n ways can be obtained, and then the process returns to S202-S204 until the frequency offsetless signal is obtained.
- the preprocessing of the n third estimated frequency offset values respectively includes:
- Determining whether the pre-processed n third estimated frequency offset values respectively converge comprises:
- n fourth estimated frequency offset values are less than or equal to a preset threshold, wherein if the n fourth estimated frequency offset values are respectively less than or equal to the preset threshold, indicating that after the current iteration The n third estimated frequency offset values converge; if the n fourth estimated frequency offset values are respectively greater than the preset threshold, it indicates that the n third estimated frequency offset values after the current iteration do not converge.
- the pre-processing that is, whether the n third estimated frequency offset values after the current iteration converge, it is generally required to determine the third estimated frequency offset value after the current iteration and the fifth estimate after the last iteration.
- the difference between the frequency offset values is less than or equal to the preset threshold.
- the difference is the fourth estimated frequency offset value.
- the preset threshold is 0.
- the corresponding n locally stored n values may be respectively updated according to the n third estimated frequency offset values after the current iteration.
- the fifth estimated frequency offset value specifically, in this embodiment, only the estimated frequency offset value after the current iteration is saved in each local register, that is, the third estimated frequency offset value after the current iteration is used as a new value.
- the fifth estimated frequency offset value replaces the original fifth estimated frequency offset value in the local register, but is not limited thereto.
- each local register may also store N fifth estimated frequency offset values according to an iterative order, wherein the Nth estimated frequency offset value is a third estimated frequency offset value after the current iteration, where N is greater than 1 a positive integer; in this case, the fifth estimated frequency offset value in the iterative operation of the n fourth estimated frequency offset values and the corresponding locally stored n estimated frequency offset values respectively is ( N-1)
- the third estimated frequency offset value after the iteration; the update of the register in this case is not limited here, and can be directly saved, or the estimated frequency offset value after the current iteration can be saved and the local register is deleted. An estimated frequency offset value will not be described here.
- performing frequency offset correction on the n second signals according to the n third estimated frequency offset values after the current iteration includes:
- each receiving structure decodes and outputs data of one transmitting antenna from data of n receiving antennas.
- only one transmitting data to be decoded by one receiving structure is concerned. Therefore, only the output phase of one transmitter and the frequency offset of one transmitter are output.
- n first estimated frequency offset values that is, estimates of the receiving end, are obtained according to n center tap coefficients corresponding to the n first correction signals and n first output phases corresponding to the n first correction signals.
- a frequency offset value obtaining a second estimated frequency offset value of the transmitting end according to the second output phase corresponding to the superposed signal; that is, calculating the estimated frequency offset by inserting a known sequence into the transmission data of the baseband signal, but according to the baseband
- the transmission data of the signal that is, the first correction signal, can obtain the respective estimated frequency offsets of the receiving end and the transmitting end, and then perform frequency offset correction on the currently received n second signal according to the estimated frequency offset of the receiving end and the transmitting end, thereby ensuring The efficient transmission of data.
- the frequency offset is estimated according to the transmission data of the baseband signal, and the transmission process of the transmission data is continuous. Therefore, the method in this embodiment has a dynamic tracking characteristic; and the estimated frequency offset of the receiving end and the transmitting end is calculated. The process does not involve high-dimensional matrix calculation, which reduces the computational complexity.
- the frequency offset of the transmitting and receiving ends can be compensated at the receiving end. Compared with the prior art, the frequency offset of the transmitting end is performed at the transmitting end by means of feedback. In terms of compensation, the complexity of the compensation system is reduced, the system construction and configuration are simplified, and the signal offset technique is used to estimate and correct the frequency offset, which reduces the limitation and selection cost of the hardware device.
- Example 3 Referring to FIG. 5, FIG. 5 is a flowchart of an embodiment of a frequency offset correction method in a distributed MIM0 system according to Embodiment 3 of the present invention;
- the frequency offset correction method in the distributed MIM0 system includes:
- the receiving and transmitting end sends n first baseband signals, digitally processes the n first baseband signals, and receives the digitally processed n first signals; and the n first signals according to the estimated frequency offset
- the frequency offset correction is performed to obtain n first correction signals.
- S301 in this embodiment is similar to S201 in Embodiment 2, and details are not described herein again. For details, refer to the related description of Embodiment 2.
- S302 Acquire n center tap coefficients of the space-time equalizer corresponding to the n-channel first correction signal, and n first output phases and superimposed signals of the phase-locked loop phase detector corresponding to the n-channel first correction signal a second output phase of the phase-locked loop phase detector, wherein the superimposed signal is a signal obtained by superimposing the n-channel first correction signals one by one.
- S302 in this embodiment is similar to S202 in Embodiment 2, and details are not described herein again. For details, refer to the related description of Embodiment 2.
- S303 Acquire n first estimated frequency offset values of the 0DUs on the n receiving branches according to the n center tap coefficients and the n first output phases, and acquire a second estimated frequency of the transmitting end according to the second output phase. Offset value.
- S303 in this embodiment is similar to S203 in Embodiment 2, and details are not described herein again. For details, refer to the related description of Embodiment 2.
- S304 Receive a digitally processed n-channel second signal, and when the decoding operation is not a linear operation, pair the n second signals according to the n first estimated frequency offset values and the second estimated frequency offset value. Perform frequency offset correction.
- the first correction signal is the first signal after the frequency offset correction processing; in the embodiment of the present invention, the frequency offset estimation is performed on the first received signal, and then the second current reception is performed. The signal is compensated for frequency offset.
- the baseband processing is required.
- the system determines whether the decoding operation in the decoding process of the MIM0 signal is a linear operation.
- the frequency offset compensation of the receiving end is performed according to the n first estimated frequency offset values before the decoding process, to obtain n first correcting signals; and the n first correcting signals are further Performing a decoding process of the MIM0 signal to obtain a decoded n-channel first correction signal; and then performing frequency offset compensation on the transmitting end of the n-channel first correction signal according to the second estimated frequency offset value before performing the decision synthesis process, The n second correction signal is obtained.
- the n first estimated frequency offset values of the 0DUs on the n receiving branches are respectively preprocessed, and the preprocessed n first estimated frequency offset values are respectively determined. Whether to converge, if yes, performing frequency offset correction on the n second signals according to the pre-processed n first estimated frequency offset values, to obtain a a correction signal; performing frequency offset correction on the first corrected signal after the decoding process according to the second estimated frequency offset value of the transmitting end, to obtain a frequency-free signal, that is, the second correction signal.
- the frequency offset value is used to compensate the frequency offset of the first modified signal after the n-channel decoding, and the n-th second correction signal is obtained.
- the second correction signal obtained at this time still has a frequency offset, and therefore, the loop needs to be looped. The above process until the frequency offset signal is obtained.
- the pre-processing the n first estimated frequency offset values of the 0DUs on the n receiving branches respectively includes: performing weighting processing on the n first estimated frequency offset values of the 0DUs on the n receiving branches Then, the first estimated frequency offset value after the weighting process is iteratively processed to obtain the first estimated frequency offset value after the pre-processing, that is, the first estimated frequency offset value after the current iteration.
- the first estimated frequency offset value after the weighting process is iteratively processed to obtain the first estimated frequency offset value after the pre-processing, that is, the first estimated frequency offset value after the current iteration.
- the method in this embodiment performs stepwise compensation according to the estimated CF0 data, and adjusts the bandwidth of the "estimation-correction" loop by the step control and the iterative update, so that the CF0 data after the stepwise compensation is processed by the MIM0 signal.
- the parameters of the equalizer and the phase-locked loop are gradually stabilized. At this time, the phase information of the extracted phase is gradually reduced, and the final drive converges to the correct CF0 compensation value, and the system enters a stable working state.
- the compensation process of the decoding system is described in detail below.
- the purpose of CF0 compensation is to remove the time-varying parameters " ⁇ and ° ⁇ in the synthesis matrix.
- the frequency offset of the receiving end is compensated on the received signal according to the first estimated frequency offset value at the receiving end, as shown in equation (6):
- ⁇ is the received signal vector when CF0 is present for the estimated CF0 of the nth receiving 0DU
- ⁇ is the estimated frequency offset parameter matrix for the receiving end
- ⁇ is the receiving end due to The frequency offset parameter matrix introduced by the difference
- H is the transmission channel matrix
- ⁇ ⁇ is the transmission terminal introduces the frequency offset parameter matrix due to the difference of L0
- S is the transmitted signal vector, which is the noise vector when CF0 exists.
- R cmp HH wl S + N" (7)
- H is the transmission channel matrix
- ⁇ ⁇ is the transmitting end
- S is the transmitted signal vector
- N is the noise vector after the CF0 of the receiving end is compensated.
- the transmitting signal ( wi ' which is subjected to the frequency offset impairment needs to be the decoding target, and the obtained decoding model is:
- ⁇ is the frequency offset parameter matrix introduced by the transmitter due to the difference of L0; for estimating S, that is, transmitting the signal estimation vector; ⁇ « The nth channel transmits CF0 on the 0DU, ⁇ is an approximation to the inverse matrix of H, ⁇ ⁇ is the received signal vector that compensates the frequency offset of the receiving end; and the two elements respectively correspond to the first receiving signal and the first The inverse mapping of the two received signals with respect to the first transmitted signal si; and the two elements respectively corresponding to the first receiving
- the decoding model is the inverse mapping of the transmission system.
- the decoded signal is compensated by using the estimated frequency offset of the transmitting end, that is, the second estimated frequency offset value of the transmitting end, to obtain a final decoded signal, as shown in formula (9):
- s is an estimate of s, that is, a transmitted signal estimation vector
- 5 is a decoded signal that is subjected to a frequency offset impairment ( ⁇ ' as a decoding target, and sn is an estimate of the 0th transmitted 0th channel CFO
- H w is the estimated frequency offset parameter matrix for the transmitting end
- ⁇ ⁇ is the frequency offset parameter matrix introduced by the transmitter due to the difference of L0, which is the estimation of S, that is, the transmitted signal estimation vector.
- the decoded signal obtained by decoding in the most ideal case is the transmitted signal, but considering the existence of undesired factors such as noise in the system, the decoding may be wrong, so the decoded signal is actually the estimation and approximation of the transmitted signal, that is, .
- n first estimated frequency offset values that is, estimates of the receiving end, are obtained according to n center tap coefficients corresponding to the n first correction signals and n first output phases corresponding to the n first correction signals.
- a frequency offset value obtaining a second estimated frequency offset value of the transmitting end according to the second output phase corresponding to the superposed signal; that is, calculating the estimated frequency offset by inserting a known sequence into the transmission data of the baseband signal, but according to the baseband
- the transmission data of the signal that is, the first correction signal, can obtain the respective estimated frequency offsets of the receiving end and the transmitting end, and then perform frequency offset correction on the currently received n second signal according to the estimated frequency offset of the receiving end and the transmitting end, thereby ensuring The efficient transmission of data.
- the frequency offset is estimated according to the transmission data of the baseband signal, and the transmission process of the transmission data is continuous. Therefore, the method in this embodiment has a dynamic tracking characteristic; and the estimated frequency offset of the receiving end and the transmitting end is calculated. The process does not involve high-dimensional matrix calculation, which reduces the computational complexity.
- the frequency offset of the transmitting and receiving ends can be compensated at the receiving end. Compared with the prior art, the frequency offset of the transmitting end is performed at the transmitting end by means of feedback. In terms of compensation, the complexity of the compensation system is reduced, the system construction and configuration are simplified, and the signal offset technique is used to estimate and correct the frequency offset, which reduces the limitation and selection cost of the hardware device.
- the embodiment provides a computer program product, the computer program product comprising computer program code, when a computer unit executes the computer program code, the computer unit performs the above embodiment 1, the embodiment 2 or the embodiment
- a computer unit executes the computer program code
- the computer unit performs the above embodiment 1, the embodiment 2 or the embodiment
- FIG. 6 is a first schematic structural diagram of an embodiment of a frequency offset correction apparatus in a distributed MIM0 system according to Embodiment 5 of the present invention.
- the frequency offset correction device in the distributed MIM0 system includes:
- the receiver 601 is configured to receive n first signals, where n is a positive integer.
- the processor 602 is configured to perform frequency offset correction processing on the n first signals to obtain n first correction signals.
- the obtaining unit 603 is configured to acquire n center tap coefficients of the space-time equalizer corresponding to the n-channel first correction signal, and n first outputs of the phase-locked loop phase detector corresponding to the n-channel first correction signal.
- the first estimation acquiring unit 604 is configured to acquire n first estimated frequency offset values according to the n center tap coefficients and the n first output phases.
- the second estimation obtaining unit 605 is configured to obtain a second estimated frequency offset value according to the second output phase.
- the receiving correction unit 606 is configured to receive n second signals, and perform frequency offset correction on the n second signals according to the n first estimated frequency offset values and the second estimated frequency offset values.
- the first estimation obtaining unit 604 includes: a first obtaining subunit 6041, a second obtaining subunit 6042, and a processing subunit 6043.
- FIG. 7 is a fifth embodiment of the present invention.
- a second schematic structural diagram of a frequency offset correction device embodiment in a distributed MIM0 system is provided;
- the first obtaining subunit 6041 is configured to obtain n first sub-estimated frequency offsets according to the n center tap coefficients.
- the second obtaining subunit 6042 is configured to acquire n second estimated frequency offsets according to the n first output phases.
- the processing sub-unit 6043 is configured to perform gain control and superposition synthesis processing on the n first sub-estimation frequency offsets and the corresponding n second sub-estimation frequency offsets to obtain n first estimated frequency offset values.
- the first obtaining subunit 6041 includes:
- phase extraction subunit configured to separately extract instantaneous phase information of the n center tap coefficients to obtain n instantaneous phase information.
- the first difference numerator unit is configured to perform differential operation on the n instantaneous phase information respectively to obtain n first frequency information.
- the limiting subunit is configured to perform limiting processing on the n first frequency information respectively to obtain n first limited frequency information.
- a first low pass filtering sub-unit configured to perform low-pass filtering processing on the n sliced first frequency information respectively to obtain n first sub-estimated frequency offsets.
- the second obtaining subunit 6042 includes:
- a second difference numerator unit configured to perform differential operations on the n first output phases to obtain n second frequency information.
- a second low pass filtering sub-unit configured to perform low-pass filtering processing on the n second frequency information respectively to obtain n second sub-estimated frequency offsets.
- the second estimation acquiring unit 605 includes:
- a third difference molecular unit configured to perform a differential operation on the second output phase to obtain third frequency information.
- a third low pass filtering sub-unit configured to perform low-pass filtering processing on the third frequency information to obtain a second estimated frequency offset value.
- the receiving correction unit 606 includes:
- a third obtaining subunit configured to perform gain control processing on the second estimated frequency offset value when the decoding operation is a linear operation, and the second estimated frequency offset value after the gain control processing and the n first An estimated frequency offset value is merged, Obtaining n third estimated frequency offset values corresponding to the first signal of the n channels.
- a first determining correction subunit configured to perform preprocessing on the n third estimated frequency offset values respectively, and respectively determine whether the preprocessed n third estimated frequency offset values converge, and if yes, respectively
- the n third estimated frequency offset values after the pre-processing are integrated to obtain n estimated phase information; and the n second signals are phase-modulated according to the n estimated phase information to obtain a frequency-free signal.
- the first judgment correction subunit includes:
- a weighting subunit configured to multiply the n third estimated frequency offset values by a preset step size to obtain the weighted n fourth estimated frequency offset values.
- an iteration sub-unit configured to iterate the n fourth estimated frequency offset values and the corresponding locally stored n fifth estimated frequency offset values to obtain n third estimated frequency offset values after the iteration.
- a determining subunit configured to determine, respectively, whether the n fourth estimated frequency offset values are less than or equal to a preset threshold, wherein if the n fourth estimated frequency offset values are respectively less than or equal to the preset threshold, The n third estimated frequency offset values after the iteration converge; if the n fourth estimated frequency offset values are respectively greater than the preset threshold, indicating that the n third estimated frequency offset values after the iteration are not convergence.
- the device further includes:
- an updating unit configured to update, according to the n third estimated frequency offset values after the iteration, the n locally estimated frequency offsets respectively corresponding to the n estimated third frequency offset values after the iteration value.
- the correcting unit 606 includes:
- a second determining correction subunit configured to perform preprocessing on the n first estimated frequency offset values respectively when the decoding operation is not a linear operation, and respectively determine whether the preprocessed n first estimated frequency offset values are Convergence, if yes, performing frequency offset correction on the n second signals according to the preprocessed n first estimated frequency offset values, to obtain a first correction signal; according to the second estimated frequency offset value pair The first correction signal after the decoding process is subjected to frequency offset correction to obtain a frequency-free signal.
- the frequency offset correction apparatus in the distributed MIM0 system in this embodiment may further include: a memory, configured to store at least one of the following information: the n first estimated frequency offset values and the second estimated frequency offset Value, n first sub-estimation frequency offset, n second sub-estimation frequency offset, n fourth estimated frequency offset value, fifth estimated frequency offset value, etc., but are not limited thereto, and are not described herein again. .
- the frequency offset correction apparatus in the distributed MIM0 system is located in a baseband processing system, and the baseband processing system further includes n space-time equalizers and (n+1) phase-locked loop phase detectors.
- FIG. 8 is a schematic diagram of signal processing of a microwave MIM0 system according to Embodiment 5 of the present invention.
- the microwave MIMO system is a distributed MIMO system.
- the n-channel baseband signal is transmitted to the n-channel receiving terminal 0DU through the n-channel receiving terminal 0DU, and the n-channel receiving terminal 0DU receives the n-baseband signal and transmits it to the n-channel baseband processing system, and the n-channel baseband is transmitted.
- the processing system processes the n-baseband signals. Since each of the transmitting terminal 0DUs and each of the receiving terminals 0DUs adopts an independent L0, the n-channel baseband signals received by the n-channel baseband processing system have frequency offsets of the transmitting end and the receiving end.
- the baseband processing system performs analog-to-digital conversion and filtering on the received baseband signal, and the frequency offset correction device processes the digitally processed digital signal, wherein the frequency offset correction device can be based on the space-time equalizer and the phase-locked loop.
- the center tap coefficient and the output phase respectively obtained by the phase detector perform frequency offset estimation, and then perform frequency offset correction processing on the received digital signal according to the value of the frequency offset estimation, and output the corrected signal to the subsequent space time equalizer and phase lock.
- the ring phase detector or the like performs decoding processing of the MIM0 signal, outputs the decoded signal, and then performs back-end processing such as decision synthesis on the decoded signal, and finally obtains the decoded single-channel signal.
- the frequency offset correction apparatus in the distributed MIM0 system acquires n first according to n center tap coefficients corresponding to the n first correction signals and n first output phases corresponding to the n first correction signals.
- An estimated frequency offset value that is, an estimated frequency offset value of the receiving end; obtaining a second estimated frequency offset value of the transmitting end according to the second output phase corresponding to the superposed signal; that is, without inserting a known sequence into the transmission data of the baseband signal
- the method calculates the estimated frequency offset, and obtains the estimated frequency offset of each of the receiving end and the transmitting end according to the transmission data of the baseband signal, that is, the first correction signal, and then compares the currently received n-channel according to the estimated frequency offset of the receiving end and the transmitting end.
- the second signal is frequency offset corrected to ensure efficient transmission of data.
- the frequency offset is estimated according to the transmission data of the baseband signal, and the transmission process of the transmission data is continuous. Therefore, the method in this embodiment has a dynamic tracking characteristic; and the estimated frequency offset of the receiving end and the transmitting end is calculated. The process does not involve high-dimensional matrix calculation, which reduces the computational complexity.
- the frequency offset of the transmitting and receiving ends can be compensated at the receiving end. Compared with the prior art, the frequency offset of the transmitting end is performed at the transmitting end by means of feedback. In terms of compensation, the complexity of the compensation system is reduced, the system construction and configuration are simplified, and the signal offset technique is used to estimate and correct the frequency offset, which reduces the limitation and selection cost of the hardware device.
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Power Engineering (AREA)
- Radio Transmission System (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
Description
一种频偏校正方法及装置 技术领域
本发明涉及通信技术领域,特别涉及一种应用于分布式 MIM0(Multiple Input Multiple Output, 多输入多输出) 系统中的频偏校正方法及装置。 背景技术
MIM0技术是一种利用多天线技术提升通信系统频谱效率的有效手段, 在无线和微波通 信中具有极高的应用价值。 在 MIM0系统中, 不同天线对构成了多个不同的子信道, 根据信 号在不同子信道上的不同传输特征, 接收端可以利用相应算法对不同发射天线上的数据进 行解码分辨, 从而达到了在同一频段上同时传输多路信息的效果, 频谱效率成倍提升。
在分布式 MIM0系统中, 天线间隔较远, 每根天线均与独立的 ODU (OutDoor Unit, 室 外单元) 连接, 各个 0DU中均包含 L0 (Local Oscillator, 本地振荡器)。 由于各个 0DU内 部 L0 器件的差异, 接收端一根天线接收到的多路基带信号间呈现不同的 CFO ( Carrier Frequency Offset, 载波频偏, 简称频偏), 使得接收端的解码系统难以收敛到稳定的解码 状态, 解码性能严重恶化。
现有技术中, 在基带信号的传输数据中插入特殊构造的已知序列, 例如 CAZAC (Const Amplitude Zero Auto Corelation, 恒包络零自相关)序列, 该序列在不同的天线上同时发 送, 利用该序列在时间上和空间上的正交性, 通过计算可以得到分布式 MIM0系统的 CF0参 数, 根据该 CF0参数实现信号的校正, 提高解码性能。
由于已知序列是插入在基带信号的传输数据中, 影响了数据的有效传输, 且根据已知 序列计算分布式 MIM0系统的 CF0参数的过程具有间歇性, 不具有动态跟踪特性。 发明内容
为了保证数据的有效传输, 本发明实施例提供了一种频偏校正方法及装置。 所述技术 方案如下:
一方面, 提供了一种分布式多输入多输出 MIM0系统中的频偏校正方法, 包括: 接收 n路第一信号, n为正整数;
对所述 n路第一信号进行频偏校正处理, 得到 n路第一校正信号;
获取所述 n路第一校正信号对应的空时均衡器的 n个中心抽头系数、 所述 n路第一校 正信号对应的锁相环鉴相器的 n个第一输出相位和叠加信号对应的锁相环鉴相器的第二输 出相位, 其中所述叠加信号为所述 n路第一校正信号逐一叠加后得到的信号;
根据所述 n个中心抽头系数和所述 n个第一输出相位获取 n个第一估计频偏值; 根据所述第二输出相位获取第二估计频偏值;
接收 n路第二信号, 根据所述 n个第一估计频偏值和所述第二估计频偏值对所述 n路 第二信号进行频偏校正。
另一方面, 提供了一种分布式多输入多输出 MIM0系统中的频偏校正装置, 包括: 接收器, 用于接收 n路第一信号, n为正整数;
处理器, 用于对所述 n路第一信号进行频偏校正处理, 得到 n路第一校正信号; 获取单元, 用于获取所述 n路第一校正信号对应的空时均衡器的 n个中心抽头系数、 所述 n路第一校正信号对应的锁相环鉴相器的 n个第一输出相位和叠加信号对应的锁相环 鉴相器的第二输出相位, 其中所述叠加信号为所述 n 路第一校正信号逐一叠加后得到的信 号;
第一估计获取单元, 用于根据所述 n个中心抽头系数和所述 n个第一输出相位获取 n 个第一估计频偏值;
第二估计获取单元, 用于根据所述第二输出相位获取第二估计频偏值;
接收校正单元, 用于接收 n路第二信号, 根据所述 n个第一估计频偏值和所述第二估 计频偏值对所述 n路第二信号进行频偏校正。
本发明实施例提供的技术方案的有益效果是: 根据 n路第一校正信号对应的 n个中心 抽头系数和所述 n路第一校正信号对应的 n个第一输出相位获取 n个第一估计频偏值, 即 接收端的估计频偏值; 根据叠加信号对应的第二输出相位获取发送端的第二估计频偏值; 也就是说无需通过在基带信号的传输数据中插入已知序列的方法计算估计频偏, 而是根据 基带信号的传输数据, 即第一校正信号便可获取接收端和发送端各自的估计频偏, 然后根 据接收端和发送端的估计频偏对当前接收的 n 路第二信号进行频偏校正, 从而保证了数据 的有效传输。
此外, 本实施例中是根据基带信号的传输数据进行频偏的估计, 且传输数据的传输过 程是连续的, 因此本实施例所述方法具有动态跟踪特性; 计算接收端和发送端的估计频偏 的过程不涉及高维度的矩阵计算, 降低了运算复杂度; 本实施例可以在接收端补偿收发两 端的频偏影响, 相比较现有技术中将发送端的频偏通过反馈的方式在发送端进行补偿而言,
降低了补偿系统的复杂度。 附图说明
为了更清楚地说明本发明实施例中的技术方案, 下面将对实施例描述中所需要使用的 附图作简单地介绍, 显而易见地, 下面描述中的附图仅仅是本发明的一些实施例, 对于本 领域普通技术人员来讲, 在不付出创造性劳动的前提下, 还可以根据这些附图获得其它的 附图。
图 1是本发明实施例 1提供的一种分布式 MIM0系统中的频偏校正方法实施例的流程图; 图 2是本发明实施例 2提供的一种分布式 MIM0系统中的频偏校正方法实施例的流程图; 图 3为本发明实施例 2提供的一种第一估计频偏值的计算流程示意图;
图 4是本发明实施例 2提供的第一估计频偏值的合成示意图;
图 5是本发明实施例 3提供的一种分布式 MIM0系统中的频偏校正方法实施例的流程图; 图 6是本发明实施例 5提供的一种分布式 MIM0系统中的频偏校正装置实施例的第一结 构示意图;
图 7是本发明实施例 5提供的一种分布式 MIM0系统中的频偏校正装置实施例的第二结 构示意图;
图 8是本发明实施例 5提供的一种微波 MIM0系统的信号处理示意图。 具体实施方式
为使本发明的目的、 技术方案和优点更加清楚, 下面将结合附图对本发明实施方式作 进一步地详细描述。
由于各个 0DU内部 L0器件的差异, 接收端一根天线接收到的多路基带信号间呈现不同 的 CF0, 这对接收端解码系统的数据解码产生较大的影响, 下面以 2*2MIM0为例, 通过对比 没有 CF0和存在 CF0时的两种传输系统来描述 CF0对数据解码的影响。
公式 (1 ) 是没有 CF0时的传输系统, 如下所示:
R H S + N
( 1 ) 其中, R为接收信号矢量, H为传输信道矩阵, S为发射信号矢量, N为噪声矢量。 在 该传输系统下, 当接收端的解码算法稳定后, 解码系统将收敛到公式 (2 ) 所示的状态, 如 下所示:
S = H' - R ( 2 )
其中, S为对 S的估计, 即发射信号估计矢量; ^为对 H的逆矩阵的逼近 公式 (3 ) 是存在 CF0时的传输系统, 如下所示:
其中, 为存在 CFO时的接收信号矢量, ^ "为第 n路发射 ODU上的 CF0, ω™为第 n 路接收 ODU上的 CF0, H为传输信道矩阵, S为发射信号矢量, N为噪声矢量, 为存在 CF0 时的传输信道矩阵, 为存在 CF0时的噪声矢量, ^为接收端由于 L0的差异而引入的 频偏参数矩阵, ^ ^为发送端由于 L0的差异而引入的频偏参数矩阵。 在该传输系统下, 解 码系统需要收敛到公式 (4 ) 所示的状态才能完成解码, 如下所示:
S = H ., ' R ( 4 ) 其中, 为对 Λ 的逆矩阵的逼近;
对比公式 (2 ) 和公式 (4 ) 可以看出, 矩阵^是一个与时间 t无关的量, 而由于存在 CF0, 矩阵 是一个随时间 t快速变化的量。 在没有 CF0的传输系统中, 解码系统容易收 敛到稳定的解码状态;而在存在 CF0的传输系统中,解码系统难以跟踪矩阵 '的快速变化, 解码性能恶化。
下述实施例可以以公式 (3 ) 所示的传输系统为例进行描述。
实施例 1
参考图 1, 图 1是本发明实施例 1提供的一种分布式 MIM0系统中的频偏校正方法实施 例的流程图;
所述分布式 MIM0系统中的频偏校正方法包括:
S 101 : 接收 n路第一信号, n为正整数。
S 102 : 对所述 n路第一信号进行频偏校正处理, 得到 n路第一校正信号。
S 103 : 获取所述 n路第一校正信号对应的空时均衡器的 n个中心抽头系数、 所述 n路 第一校正信号对应的锁相环鉴相器的 n个第一输出相位和叠加信号对应的锁相环鉴相器的 第二输出相位, 其中所述叠加信号为所述 n路第一校正信号逐一叠加后得到的信号。
S 104: 根据所述 n个中心抽头系数和所述 n个第一输出相位获取 n个第一估计频偏值。
S 105 : 根据所述第二输出相位获取第二估计频偏值。
S 106 : 接收 n路第二信号, 根据所述 n个第一估计频偏值和所述第二估计频偏值对所 述 n路第二信号进行频偏校正。
本实施例中, 根据 n路第一校正信号对应的 n个中心抽头系数和所述 n路第一校正信 号对应的 n个第一输出相位获取 n个第一估计频偏值, 即接收端的估计频偏值; 根据叠加
信号对应的第二输出相位获取发送端的第二估计频偏值; 也就是说无需通过在基带信号的 传输数据中插入已知序列的方法计算估计频偏, 而是根据基带信号的传输数据, 即第一校 正信号便可获取接收端和发送端各自的估计频偏, 然后根据接收端和发送端的估计频偏对 当前接收的 n路第二信号进行频偏校正, 从而保证了数据的有效传输。
此外, 本实施例中是根据基带信号的传输数据进行频偏的估计, 且传输数据的传输过 程是连续的, 因此本实施例所述方法具有动态跟踪特性; 计算接收端和发送端的估计频偏 的过程不涉及高维度的矩阵计算, 降低了运算复杂度; 本实施例可以在接收端补偿收发两 端的频偏影响, 相比较现有技术中将发送端的频偏通过反馈的方式在发送端进行补偿而言, 降低了补偿系统的复杂度。 实施例 2
参考图 2, 图 2是本发明实施例 2提供的一种分布式 MIM0系统中的频偏校正方法实施 例的流程图;
所述分布式 MIM0系统中的频偏校正方法包括:
S201 : 接收发送端发送的 n路第一基带信号, 对所述 n路第一基带信号进行数字处理, 接收经过数字处理后的 n路第一信号;根据估计频偏对所述 n路第一信号进行频偏校正, 获 得 n路第一校正信号。
此步骤中, 当接收端首次接收发送端发送的第一基带信号时, 接收端依次通过接收天 线、 0DU后, 由基带处理系统, 如 IDU ( InDoor Unit, 室内单元) 接收处理所述第一基带 信号, 对所述第一基带信号进行模数转换和滤波处理, 生成第一信号, 其中第一信号为数 字信号。 接收端基带处理系统的 n个接收支路上均接收一个所述第一基带信号, 每个接收 支路均按照上述流程对所述第一基带信号进行处理, 生成 n 路第一信号; 其中, 第一信号 中包含了接收端的 CF0和发送端的 CF0。
当接收端首次接收发送端发送的第一基带信号时, 该估计频偏为 0; 于是根据所述估计 频偏对所述 n路第一信号进行频偏估计得到的 n路第一校正信号仍为所述 n路第一信号; 其中第一校正信号中也包含了接收端的 CF0和发送端的 CF0。
S202: 获取所述 n路第一校正信号对应的空时均衡器的 n个中心抽头系数、 所述 n路 第一校正信号对应的锁相环鉴相器的 n个第一输出相位和叠加信号对应的锁相环鉴相器的 第二输出相位, 其中所述叠加信号为所述 n路第一校正信号逐一叠加后得到的信号。
本实施例中, 接收端的基带处理系统得到所述 n路第一校正信号后, 对所述 n路第一 校正信号进行 MIM0 信号的解码处理, 具体地, 可以对所述 n 路第一校正信号依次通过
STE (Space Time Equal izer,空时均衡器)和锁相环鉴相器分别进行空时均衡处理和锁相等 处理, 实现解码, 得到解码后的 n路第一校正信号, 再对所述解码后的 n路第一校正信号 进行判决合成处理, 得到解码后的单路信号。 其中, 空时均衡器和锁相环鉴相器随着信道 中传输信号的不同其输出也会随之改变, n为正整数。
当所述 n路第一校正信号依次通过 STE和锁相环鉴相器时, 分别获取所述 n路第一校 正信号对应的信号通道上 STE的 n个中心抽头系数、 所述 n路第一校正信号对应的信号通 道上锁相环鉴相器的 n个第一输出相位、 和所述 n路第一校正信号逐一叠加后得到的叠加 信号对应的锁相环鉴相器的第二输出相位。
其中, 在自适应的 STE环路中, 频偏会持续改变判决误差的梯度方向, 形成一个统计 偏置量, 由于自适应 STE会跟踪误差的梯度方向, 因此 STE的中心抽头系数便可指示频偏 的方向, 其中支路通道的 STE的中心抽头系数反映了接收端不同 0DU的 CF0信息。
由于锁相环能够跟踪和锁定信号的相位偏移, 在跟踪的过程中, 锁相环鉴相器输出的 相位也会按照频偏的方向随时间累加, 因此锁相环鉴相器的输出相位能够指示频偏, 其中 支路通道的锁相环鉴相器的输出相位, 即第一输出相位反映了接收端不同 0DU的 CF0信息; 叠加通道的锁相环鉴相器的输出相位, 即第二输出相位反映了解码信号对应发送端 0DU 的 CF0信息。
S203: 根据所述 n个中心抽头系数和所述 n个第一输出相位获取 n个接收支路上 0DU 的 n个第一估计频偏值, 根据所述第二输出相位获取发送端的第二估计频偏值。
本实施例中, 通过对 STE和锁相环的信息对 CF0进行估计, 即通过对 STE的中心抽头 系数和锁相环鉴相器的输出相位对 CF0进行估计, 从而实现盲频偏估计, 无需依赖已知序 列的计算, 便可得到发送端和接收端各自的估计频偏。
具体地, 可参照图 3所示, 图 3为本发明实施例 2提供的一种第一估计频偏值的计算 流程示意图;
所述第一估计频偏值的计算过程包括:
S203a: 根据所述 n个中心抽头系数获取 n个接收支路上 0DU的 n个第一子估计频偏。 具体地, 分别提取所述 n个中心抽头系数的瞬时相位信息, 得到 n个瞬时相位信息; 分别对所述 n个瞬时相位信息进行差分运算, 得到 n个第一频率信息; 分别对所述 n个第 一频率信息进行限幅处理, 得到 n个限幅后的第一频率信息; 分别对所述 n个限幅后的第 一频率信息进行低通滤波处理, 得到 n个接收支路上 0DU的 n个第一子估计频偏。
S203b: 根据所述 n个第一输出相位获取所述 n个接收支路上 0DU的 n个第二子估计频 偏。
具体地, 分别对所述 n个第一输出相位进行差分运算, 得到 n个第二频率信息; 分别 对所述 n个第二频率信息进行低通滤波处理, 得到所述 n个接收支路上 0DU的 n个第二子 估计频偏。
S203c: 将所述 n个第一子估计频偏分别与对应接收支路上 0DU的 n个第二子估计频偏 进行增益控制和叠加合成处理, 得到所述 n个接收支路上 0DU的 n个第一估计频偏值。
具体地, 根据估计数据的可信度分别对各个第一子估计频偏和第二子估计频偏进行增 益控制, 即加权控制, 然后对增益控制后的各个第一子估计频偏与对应的所述增益控制后 的第二子估计频偏进行叠加合成, 得到所述 n个接收支路上 0DU的 n个第一估计频偏值, 如图 4所示, 图 4是本发明实施例 2提供的第一估计频偏值的合成示意图。 其中, 表示 第 n个接收支路上 0DU的第一子估计频偏, "表示第 n个接收支路上 0DU的第二子估计频 偏, /表示第 n个接收支路上 0DU的第一估计频偏值。
STE的中心抽头系数和第一输出相位均反映了接收端不同 0DU的 CF0信息, 通过根据 STE的中心抽头系数获取的第一子估计频偏,和根据第一输出相位获取的第二子估计频偏进 行的增益控制等处理方式将二者结合可以进一步提高估计跟踪的鲁棒性。
此步骤中, 根据所述第二输出相位获取发送端的第二估计频偏值的流程与 S203b类似, 具体为: 对所述第二输出相位进行差分运算, 得到第三频率信息; 对所述第三频率信息进 行低通滤波处理, 得到发送端的第二估计频偏值。
S204: 当解码运算是线性运算时, 根据所述 n个第一估计频偏值和所述第二估计频偏 值, 获取 n路所述第一信号对应的 n个第三估计频偏值。
此步骤中, 在得到接收端 0DU的估计频偏, 即所述 n个第一估计频偏值, 和发送端 0DU 的估计频偏, 即所述第二估计频偏值后, 需要由基带处理系统判断 MIM0信号的解码处理中 的解码运算是否为线性运算, 其中通常情况下解码运算满足线性。
当解码运算是线性运算时, 发送端 0DU 的频偏补偿可以交换到解码处理之前, 与接收 端 0DU的频偏补偿合并完成, 即将所述 n个接收支路上 0DU的 n个第一估计频偏值和所述 发送端的第二估计频偏值合并后一起进行补偿接收端和发送端的频偏。
具体地, 根据所述 n个接收支路上 0DU的 n个第一估计频偏值和所述发送端的第二估 计频偏值, 获取 n路所述第一信号对应的 n个第三估计频偏值。
其中, 根据估计数据的可信度对第二估计频偏值进行增益控制处理, 将所述增益控制 处理后的第二估计频偏值与所述 n个接收支路上 0DU的 n个第一估计频偏值均进行合并, 即将第二估计频偏值与每个第一估计频偏值相加, 得到 n路所述第一信号对应的 n个第三 估计频偏值。
S205: 接收经过数字处理后的 n路第二信号, 根据所述 n个第三估计频偏值对所述 n 路第二信号进行频偏校正。
本实施例中所述第一校正信号即为经过频偏校正处理后的第一信号; 本发明实施例就 是利用对上一次接收的第一信号进行频偏估计后, 再对当前接收的第二信号进行频偏补偿。
在得到所述 n个第三估计频偏值后, 对所述 n个第三估计频偏值进行预处理, 分别判 断所述预处理后的 n个第三估计频偏值是否收敛, 如果是, 根据所述预处理后的 n个第三 估计频偏值分别对所述 n 路第二信号进行频偏校正, 得到无频偏信号; 如果否, 根据所述 预处理后的 n个第三估计频偏值分别对所述 n路第二信号进行频偏校正, 可以得到 n路所 述第一校正信号, 然后可以返回执行 S202-S204, 直至得到无频偏信号。
其中, 所述对所述 n个第三估计频偏值分别进行预处理包括:
将所述 n个第三估计频偏值分别与预设步长相乘, 得到 n个加权后的第四估计频偏值; 将所述 n个第四估计频偏值分别与对应本地存储的 n个第五估计频偏值进行叠加, 得 到迭代后的 n个第三估计频偏值;
所述分别判断所述预处理后的 n个第三估计频偏值是否收敛包括:
分别判断所述 n个第四估计频偏值是否小于或等于预设阈值, 其中若所述 n个第四估 计频偏值分别小于或等于所述预设阈值, 则表示所述本次迭代后的 n个第三估计频偏值收 敛; 若所述 n个第四估计频偏值分别大于所述预设阈值, 则表示所述本次迭代后的 n个第 三估计频偏值不收敛。
具体地, 判断所述预处理后, 即本次迭代后的 n个第三估计频偏值是否收敛, 一般需 要判断本次迭代后的第三估计频偏值与上一次迭代后的第五估计频偏值的差是否小于等于 预设阈值, 本实施例中, 该差即为第四估计频偏值; 优选的, 所述预设阈值为 0。
本实施例中, 在获取本次迭代后的 n个第三估计频偏值之后, 还可以根据所述本次迭 代后的 n个第三估计频偏值分别更新所述对应本地存储的 n个第五估计频偏值, 具体地, 本实施例优选的, 每个本地寄存器中只保存当前迭代后的估计频偏值, 也就是将所述本次 迭代后的第三估计频偏值作为新的第五估计频偏值替换本地寄存器中原有的第五估计频偏 值, 但是并不局限于此。 本实施例中, 每个本地寄存器也可以按照迭代顺序保存 N个第五 估计频偏值, 其中第 N个估计频偏值为本次迭代后的第三估计频偏值, 其中 N为大于 1的 正整数; 这种情况下, 所述将所述 n个第四估计频偏值分别与对应本地存储的 n个第五估 计频偏值进行迭代操作中的第五估计频偏值为第 (N-1 ) 次迭代后的第三估计频偏值; 此种 情况下的寄存器的更新在此不作任何限定, 可以直接保存, 也可以保存当前迭代后的估计 频偏值并删除本地寄存器中第一个估计频偏值, 在此不再赘述。
此步骤中, 所述根据所述本次迭代后的 n个第三估计频偏值分别对所述 n路第二信号 进行频偏校正包括:
分别对所述本次迭代后的 n个第三估计频偏值进行积分运算, 得到 n个估计相位信息; 根据所述 n个估计相位信息对当前接收的 n路第二信号进行调相。
对于公式 (3 ) 所示的传输系统而言, 以第一路信号 s i 的 CF0补偿为例, 按照上述频 偏校正的方法可以收敛到公式 (5 ) 所示的状态, 如下所示:
Q
( 5 )
Q ^-;'«2+¾'1)^ 其中, 为对第 1路发射信号 s i的估计, 即第 1路发射信号 s i的估计矢量; 和 分别为 的两个元素,对应了第 1路接收信号和第 路接收信号相对于第 1路发射信号 s i 的逆映射; ί¾为第 1路接收 0DU的估计 CF0、 β ^为第 1路发送 0DU的估计 CFO; R 为补 偿了接收端频偏的接收信号矢量; 为存在 CF0时的接收信号矢量。
本实施例中, 一个 n发 n收的 MIM0系统中, 发送端有 n个频偏,接收端也有 n个频偏, 其中每个接收天线的数据都是 n个发射天线数据的混合。 完整的接收系统中, 有 n个相似 的接收结构, 每个接收结构从 n个接收天线的数据中解码输出一个发射天线的数据, 本实 施例中只关注一个接收结构要解码的那路发射数据, 因此, 只输出一个发射端的输出相位 和一个发射端的频偏。
本实施例中, 根据 n路第一校正信号对应的 n个中心抽头系数和所述 n路第一校正信 号对应的 n个第一输出相位获取 n个第一估计频偏值, 即接收端的估计频偏值; 根据叠加 信号对应的第二输出相位获取发送端的第二估计频偏值; 也就是说无需通过在基带信号的 传输数据中插入已知序列的方法计算估计频偏, 而是根据基带信号的传输数据, 即第一校 正信号便可获取接收端和发送端各自的估计频偏, 然后根据接收端和发送端的估计频偏对 当前接收的 n路第二信号进行频偏校正, 从而保证了数据的有效传输。
此外, 本实施例中是根据基带信号的传输数据进行频偏的估计, 且传输数据的传输过 程是连续的, 因此本实施例所述方法具有动态跟踪特性; 计算接收端和发送端的估计频偏 的过程不涉及高维度的矩阵计算, 降低了运算复杂度; 本实施例可以在接收端补偿收发两 端的频偏影响, 相比较现有技术中将发送端的频偏通过反馈的方式在发送端进行补偿而言, 降低了补偿系统的复杂度, 简化系统构建与配置; 利用信号处理技术估计和校正频偏, 降 低了硬件器件的限制和选择成本。 实施例 3
参考图 5, 图 5是本发明实施例 3提供的一种分布式 MIM0系统中的频偏校正方法实施 例的流程图;
所述分布式 MIM0系统中的频偏校正方法包括:
S301 : 接收发送端发送 n路第一基带信号, 对所述 n路第一基带信号进行数字处理, 接收经过数字处理后的 n路第一信号; 根据估计频偏对所述 n路第一信号进行频偏校正, 获得 n路第一校正信号。
本实施例中的 S301与实施例 2中的 S201类似, 在此不再赘述, 具体可参照实施例 2 的相关描述。
S302: 获取所述 n路第一校正信号对应的空时均衡器的 n个中心抽头系数、 所述 n路 第一校正信号对应的锁相环鉴相器的 n个第一输出相位和叠加信号对应的锁相环鉴相器的 第二输出相位, 其中所述叠加信号为所述 n路第一校正信号逐一叠加后得到的信号。
本实施例中的 S302与实施例 2中的 S202类似, 在此不再赘述, 具体可参照实施例 2 的相关描述。
S303: 根据所述 n个中心抽头系数和所述 n个第一输出相位获取 n个接收支路上 0DU 的 n个第一估计频偏值, 根据所述第二输出相位获取发送端的第二估计频偏值。
本实施例中的 S303与实施例 2中的 S203类似, 在此不再赘述, 具体可参照实施例 2 的相关描述。
S304: 接收经过数字处理后的 n路第二信号, 当解码运算不是线性运算时, 根据所述 n 个第一估计频偏值和所述第二估计频偏值对所述 n路第二信号进行频偏校正。
本实施例中所述第一校正信号即为经过频偏校正处理后的第一信号; 本发明实施例就 是利用对上一次接收的第一信号进行频偏估计后, 再对当前接收的第二信号进行频偏补偿。
此步骤中, 在得到接收端 0DU的估计频偏, 即所述 n个第一估计频偏值, 和发送端 0DU 的估计频偏, 即所述第二估计频偏值后, 需要由基带处理系统判断 MIM0信号的解码处理中 的解码运算是否为线性运算。
当解码运算不是线性运算时, 需要在解码处理之前先根据所述 n个第一估计频偏值进 行接收端的频偏补偿, 得到 n路第一校正信号; 再对所述 n路第一校正信号进行 MIM0信号 的解码处理, 得到解码后的 n 路第一校正信号; 然后在进行判决合成处理之前根据所述第 二估计频偏值对所述 n路第一校正信号进行发送端的频偏补偿, 得到 n路第二校正信号。
具体地, 当解码运算不是线性运算时, 对所述 n个接收支路上 0DU的 n个第一估计频 偏值分别进行预处理, 分别判断所述预处理后的 n个第一估计频偏值是否收敛, 如果是, 根据所述预处理后的 n个第一估计频偏值分别对所述 n路第二信号进行频偏校正, 得到第
一校正信号; 根据所述发送端的第二估计频偏值对解码处理后的所述第一校正信号进行频 偏校正, 得到无频偏信号, 即所述第二校正信号。 如果所述预处理后的 n个第一估计频偏 值不收敛, 根据所述预处理后的 n个第一估计频偏值分别对当前接收的 n路第二信号进行 频偏校正, 可以得到 n路所述第一校正信号, 然后可以返回执行 S302-S304, 直至得到无频 偏信号;
在得到所述 n路第一校正信号后,对所述 n路第一校正信号进行 MIM0信号的解码处理, 得到 n 路解码后的第一校正信号; 在进行判决处理之前根据所述第二估计频偏值对所述 n 路解码后的第一校正信号进行发送端的频偏补偿, 得到 n 路第二校正信号, 此时得到的第 二校正信号仍然存在频偏, 因此还需要循环本实施例的上述流程, 直至得到无频偏信号。
所述对所述 n个接收支路上 0DU的 n个第一估计频偏值分别进行预处理包括: 对所述 所述 n个接收支路上 0DU的 n个第一估计频偏值进行一次加权处理, 然后对所述加权处理 后的第一估计频偏值进行迭代处理, 得到预处理后的第一估计频偏值, 即本次迭代后的第 一估计频偏值, 具体可参照实施例 2的相关描述。
本实施例所述方法是根据估计的 CF0数据进行步进式补偿, 通过步长控制和迭代更新 调整 "估计-校正"环路的带宽, 使得逐步补偿后的 CF0数据在进行 MIM0信号处理时, 均 衡器和锁相环的参数逐步稳定, 此时, 提取的相位信息的变化逐步减小, 最终驱动收敛于 正确的 CF0补偿值, 系统进入稳定的工作状态。
为了方便理解, 下面详细描述解码系统的补偿过程, 对于公式 (3) 所示的传输系统而 言, CF0补偿的目的是去除合成矩阵 中的时变参量 "^和 °^。
首先根据接收端的第一估计频偏值在接收信号上补偿接收端的频偏 如公式 (6) 所示:
0
R Rc =Hwr((Hwr-H-Hwt) -S + N') (6)
0 e 其中 为补偿了接收端频偏的接收信号矢量, ωη为对第 n路接收 0DU的估计 CF0 存在 CF0 时的接收信号矢量, ^为对接收端的估计频偏参数矩阵, ^为接收端由于 的差异而引入的频偏参数矩阵, H为传输信道矩阵, ^ ^为发送端由于 L0的差异而引入 频偏参数矩阵, S为发射信号矢量, 为存在 CF0时的噪声矢量。
当接收端的 CF0被准确估计并补偿后, 传输系统变为:
Rcmp =H Hwl S + N" (7) 其中, 为补偿了接收端频偏的接收信号矢量, H为传输信道矩阵, ^ ^为发送端由
于 L0的差异而引入的频偏参数矩阵, S为发射信号矢量, N" 为接收端的 CF0被补偿后的 噪声矢量。
此时, 系统中只有发送端的 0DU残余的频偏 , 为了消除发送端的 CF0对解码系统的 影响, 需要将受到频偏损伤的发送信号( wi ' 作为解码目标, 得到的解码模型为:
eJ。w 0 h '、、 h
S = H ' R ■R
0 ejw'2'
( 8 ) 其中, 。为将受到频偏损伤的发送信号 作为解码目标得到的解码后的信号, ^为发送端由于 L0的差异而引入的频偏参数矩阵; 为对 S的估计, 即发射信号估计矢 量; ^«为第 n路发射 0DU上的 CF0, ^为对 H的逆矩阵的逼近, Λ^为补偿了接收端频偏 的接收信号矢量; 和 分别为 的两个元素,对应了第 1路接收信号和第 2路接收信号 相对于第 1路发射信号 s i的逆映射; 和 分别为 的两个元素, 对应了第 1路接收
R
信号和第 2路接收信号相对于第 2路发射信号 s2的逆映射; 为补偿了接收端频偏的接 收信号矢量。
其中, 在数学模型上, 解码模型是传输系统的逆映射。
S
最后, 利用估计的发送端频偏, 即发送端的第二估计频偏值对解码后的信号 进行补 偿, 得到最终的解码信号, 如公式 (9 ) 所示:
S ( 9 )
0 其中, s为对 s的估计,即发射信号估计矢量; 5 为将受到频偏损伤的发送信号(^^ ' 作为解码目标得到的解码后的信号, 《s n为第 n路发送 0DU的估计 CFO; Hw 为对发送端的 估计频偏参数矩阵; ^ ^为发送端由于 L0的差异而引入的频偏参数矩阵, 为对 S的估计, 即发射信号估计矢量。
其中, 最理想的情况下解码得到的解码信号就是发送信号, 但考虑到系统中噪声等不 理想因素的存在, 解码可能会出现错误, 因此解码信号实际上是对发送信号的估计和逼近, 即 。
此时, 解码系统的最终收敛状态为^, 如公式(8 )所示, 没有时变分量的影响, 实现 了接收端对所有分布式 CF0的收发端频偏的补偿。
本实施例中, 根据 n路第一校正信号对应的 n个中心抽头系数和所述 n路第一校正信 号对应的 n个第一输出相位获取 n个第一估计频偏值, 即接收端的估计频偏值; 根据叠加 信号对应的第二输出相位获取发送端的第二估计频偏值; 也就是说无需通过在基带信号的 传输数据中插入已知序列的方法计算估计频偏, 而是根据基带信号的传输数据, 即第一校 正信号便可获取接收端和发送端各自的估计频偏, 然后根据接收端和发送端的估计频偏对 当前接收的 n路第二信号进行频偏校正, 从而保证了数据的有效传输。
此外, 本实施例中是根据基带信号的传输数据进行频偏的估计, 且传输数据的传输过 程是连续的, 因此本实施例所述方法具有动态跟踪特性; 计算接收端和发送端的估计频偏 的过程不涉及高维度的矩阵计算, 降低了运算复杂度; 本实施例可以在接收端补偿收发两 端的频偏影响, 相比较现有技术中将发送端的频偏通过反馈的方式在发送端进行补偿而言, 降低了补偿系统的复杂度, 简化系统构建与配置; 利用信号处理技术估计和校正频偏, 降 低了硬件器件的限制和选择成本。 实施例 4
本实施例提供了一种计算机程序产品, 所述计算机程序产品包括计算机程序代码, 当 一个计算机单元执行所述计算机程序代码时, 所述计算机单元执行如上述实施例 1、 实施例 2或实施例 3所记载的动作, 具体可参见实施例 1、 实施例 2或实施例 3的相关描述, 在此 不再赘述。 实施例 5
参考图 6, 图 6是本发明实施例 5提供的一种分布式 MIM0系统中的频偏校正装置实施 例的第一结构示意图;
所述分布式 MIM0系统中的频偏校正装置包括:
接收器 601, 用于接收 n路第一信号, n为正整数。
处理器 602, 用于对所述 n路第一信号进行频偏校正处理, 得到 n路第一校正信号。 获取单元 603,用于获取所述 n路第一校正信号对应的空时均衡器的 n个中心抽头系数、 所述 n路第一校正信号对应的锁相环鉴相器的 n个第一输出相位和叠加信号对应的锁相环 鉴相器的第二输出相位, 其中所述叠加信号为所述 n 路第一校正信号逐一叠加后得到的信 号。
第一估计获取单元 604,用于根据所述 n个中心抽头系数和所述 n个第一输出相位获取 n个第一估计频偏值。
第二估计获取单元 605, 用于根据所述第二输出相位获取第二估计频偏值。 接收校正单元 606, 用于接收 n路第二信号, 根据所述 n个第一估计频偏值和所述第二 估计频偏值对所述 n路第二信号进行频偏校正。
在一种实施方式中, 所述第一估计获取单元 604包括: 第一获取子单元 6041、 第二获 取子单元 6042和处理子单元 6043, 如图 7所示, 图 7是本发明实施例 5提供的一种分布式 MIM0系统中的频偏校正装置实施例的第二结构示意图;
所述第一获取子单元 6041,用于根据所述 n个中心抽头系数获取 n个第一子估计频偏。 所述第二获取子单元 6042,用于根据所述 n个第一输出相位获取 n个第二子估计频偏。 所述处理子单元 6043, 用于将所述 n个第一子估计频偏与对应的 n个第二子估计频偏 进行增益控制和叠加合成处理, 得到 n个第一估计频偏值。
其中, 所述第一获取子单元 6041包括:
相位提取子单元, 用于分别提取所述 n个中心抽头系数的瞬时相位信息, 得到 n个瞬 时相位信息。
第一差分子单元, 用于分别对所述 n个瞬时相位信息进行差分运算, 得到 n个第一频 率信息。
限幅子单元, 用于分别对所述 n个第一频率信息进行限幅处理, 得到 n个限幅后的第 一频率信息。
第一低通滤波子单元, 用于分别对所述 n个限幅后的第一频率信息进行低通滤波处理, 得到 n个第一子估计频偏。
所述第二获取子单元 6042包括:
第二差分子单元, 用于分别对所述 n个第一输出相位进行差分运算, 得到 n个第二频 率信息。
第二低通滤波子单元, 用于分别对所述 n 个第二频率信息进行低通滤波处理, 得到 n 个第二子估计频偏。
在上述实施方式的基础上, 所述第二估计获取单元 605包括:
第三差分子单元, 用于对所述第二输出相位进行差分运算, 得到第三频率信息。
第三低通滤波子单元, 用于对所述第三频率信息进行低通滤波处理, 得到第二估计频 偏值。
在上述实施方式的基础上, 所述接收校正单元 606包括:
第三获取子单元, 用于当解码运算是线性运算时, 对所述第二估计频偏值进行增益控 制处理, 将所述增益控制处理后的第二估计频偏值与所述 n个第一估计频偏值进行合并,
得到 n路所述第一信号对应的 n个第三估计频偏值。
第一判断校正子单元, 用于对所述 n个第三估计频偏值分别进行预处理, 分别判断所 述预处理后的 n个第三估计频偏值是否收敛, 如果是, 分别对所述预处理后的 n个第三估 计频偏值进行积分运算, 得到 n个估计相位信息; 根据所述 n个估计相位信息对所述 n路 第二信号进行调相, 得到无频偏信号。
所述第一判断校正子单元包括:
加权子单元, 用于将所述 n个第三估计频偏值分别与预设步长相乘, 得到加权后的 n 个第四估计频偏值。
迭代子单元, 用于将所述 n个第四估计频偏值与对应本地存储的 n个第五估计频偏值 进行迭代, 得到迭代后的 n个第三估计频偏值。
判断子单元, 用于分别判断所述 n个第四估计频偏值是否小于或等于预设阈值, 其中 若所述 n个第四估计频偏值分别小于或等于所述预设阈值, 则表示所述迭代后的 n个第三 估计频偏值收敛; 若所述 n个第四估计频偏值分别大于所述预设阈值, 则表示所述迭代后 的 n个第三估计频偏值不收敛。
在另一种实施方式中, 所述装置还包括:
更新单元, 用于所述得到迭代后的 n个第三估计频偏值之后, 根据所述迭代后的 n个 第三估计频偏值分别更新所述对应本地存储的 n个第五估计频偏值。
再一种实施方式中, 所述校正单元 606包括:
第二判断校正子单元, 用于当解码运算不是线性运算时, 对所述 n个第一估计频偏值 分别进行预处理, 分别判断所述预处理后的 n个第一估计频偏值是否收敛, 如果是, 根据 所述预处理后的 n个第一估计频偏值分别对所述 n路第二信号进行频偏校正, 得到第一校 正信号; 根据所述第二估计频偏值对解码处理后的所述第一校正信号进行频偏校正, 得到 无频偏信号。
本实施例中所述分布式 MIM0系统中的频偏校正装置还可以包括: 存储器, 用于存储下 述信息中的至少一种: 所述 n个第一估计频偏值、 第二估计频偏值、 n个第一子估计频偏、 n个第二子估计频偏、 n个第四估计频偏值、 第五估计频偏值等数值, 但是并不局限于此, 在此不再赘述。
本实施例所述的分布式 MIM0系统中的频偏校正装置位于基带处理系统中, 所述基带处 理系统还包括 n个空时均衡器和 (n+1 ) 个锁相环鉴相器。
下面以微波 MIM0为例进行描述, 参考图 8所示, 图 8是本发明实施例 5提供的一种微 波 MIM0系统的信号处理示意图;
微波 MIMO系统为分布式 MIMO系统, n路基带信号通过 n路接收端 0DU传输至 n路接收 端 0DU, n路接收端 0DU接收 n路基带信号后传输至 n路基带处理系统, 由 n路基带处理系 统对 n路基带信号进行处理, 由于各个发送端 0DU和各个接收端 0DU均采用独立的 L0, 使 得 n路基带处理系统接收到的 n路基带信号具有发送端和接收端的频偏。
基带处理系统对接收的基带信号进行模数转换和滤波等数字前端的处理, 频偏校正装 置对数字处理后的数字信号进行处理, 其中频偏校正装置可以根据从空时均衡器和锁相环 鉴相器分别获取的中心抽头系数和输出相位进行频偏估计, 然后根据频偏估计的值对接收 的数字信号进行频偏校正处理, 输出校正后的信号至后续的空时均衡器和锁相环鉴相器等 进行 MIM0信号的解码处理, 输出解码后的信号, 然后对解码后的信号进行判决合成等后端 处理, 最终得到解码后的单路信号。
本实施例中, 分布式 MIM0系统中的频偏校正装置根据 n路第一校正信号对应的 n个中 心抽头系数和所述 n路第一校正信号对应的 n个第一输出相位获取 n个第一估计频偏值, 即接收端的估计频偏值; 根据叠加信号对应的第二输出相位获取发送端的第二估计频偏值; 也就是说无需通过在基带信号的传输数据中插入已知序列的方法计算估计频偏, 而是根据 基带信号的传输数据, 即第一校正信号便可获取接收端和发送端各自的估计频偏, 然后根 据接收端和发送端的估计频偏对当前接收的 n 路第二信号进行频偏校正, 从而保证了数据 的有效传输。
此外, 本实施例中是根据基带信号的传输数据进行频偏的估计, 且传输数据的传输过 程是连续的, 因此本实施例所述方法具有动态跟踪特性; 计算接收端和发送端的估计频偏 的过程不涉及高维度的矩阵计算, 降低了运算复杂度; 本实施例可以在接收端补偿收发两 端的频偏影响, 相比较现有技术中将发送端的频偏通过反馈的方式在发送端进行补偿而言, 降低了补偿系统的复杂度, 简化系统构建与配置; 利用信号处理技术估计和校正频偏, 降 低了硬件器件的限制和选择成本。 需要说明的是, 本说明书中的各个实施例均采用递进的方式描述, 每个实施例重点说 明的都是与其它实施例的不同之处, 各个实施例之间相同相似的部分互相参见即可。 对于 装置类实施例而言, 由于其与方法实施例基本相似, 所以描述的比较简单, 相关之处参见 方法实施例的部分说明即可。
需要说明的是, 在本文中, 诸如第一和第二等之类的关系术语仅仅用来将一个实体或 者操作与另一个实体或操作区分开来, 而不一定要求或者暗示这些实体或操作之间存在任 何这种实际的关系或者顺序。 而且, 术语 "包括"、 "包含"或者其任何其它变体意在涵盖
非排它性的包含, 从而使得包括一系列要素的过程、 方法、 物品或者设备不仅包括那些要 素, 而且还包括没有明确列出的其它要素, 或者是还包括为这种过程、 方法、 物品或者设 备所固有的要素。 在没有更多限制的情况下, 由语句 "包括一个…… " 限定的要素, 并不 排除在包括所述要素的过程、 方法、 物品或者设备中还存在另外的相同要素。
本领域普通技术人员可以理解实现上述实施例的全部或部分步骤可以通过硬件来完 成, 也可以通过程序来指令相关的硬件完成, 所述的程序可以存储于一种计算机可读存储 介质中, 上述提到的存储介质可以是只读存储器, 磁盘或光盘等。 以上所述仅为本发明的较佳实施例, 并不用以限制本发明, 凡在本发明的原则之内, 所作的任何修改、 等同替换、 改进等, 均应包含在本发明的保护范围之内。
Claims
1、 一种分布式多输入多输出 MIM0系统中的频偏校正方法, 其特征在于, 包括: 接收 n路第一信号, n为正整数;
对所述 n路第一信号进行频偏校正处理, 得到 n路第一校正信号;
获取所述 n路第一校正信号对应的空时均衡器的 n个中心抽头系数、 所述 n路第一校正 信号对应的锁相环鉴相器的 n个第一输出相位和叠加信号对应的锁相环鉴相器的第二输出相 位, 其中所述叠加信号为所述 n路第一校正信号逐一叠加后得到的信号;
根据所述 n个中心抽头系数和所述 n个第一输出相位获取 n个第一估计频偏值; 根据所述第二输出相位获取第二估计频偏值;
接收 n路第二信号, 根据所述 n个第一估计频偏值和所述第二估计频偏值对所述 n路第 二信号进行频偏校正。
2、 根据权利要求 1所述的方法, 其特征在于, 所述根据所述 n个中心抽头系数和所述 n 个第一输出相位获取 n个第一估计频偏值包括:
根据所述 n个中心抽头系数获取 n个第一子估计频偏;
根据所述 n个第一输出相位获取 n个第二子估计频偏;
将所述 n个第一子估计频偏与对应的 n个第二子估计频偏进行增益控制和叠加合成处理, 得到 n个第一估计频偏值。
3、根据权利要求 2所述的方法, 其特征在于, 所述根据所述 n个中心抽头系数获取 n个 第一子估计频偏包括:
分别提取所述 n个中心抽头系数的瞬时相位信息, 得到 n个瞬时相位信息;
分别对所述 n个瞬时相位信息进行差分运算, 得到 n个第一频率信息;
分别对所述 n个第一频率信息进行限幅处理, 得到 n个限幅后的第一频率信息; 分别对所述 n个限幅后的第一频率信息进行低通滤波处理, 得到 n个第一子估计频偏。
4、根据权利要求 2或 3所述的方法, 其特征在于, 所述根据所述 n个第一输出相位获取 n个第二子估计频偏包括: 分别对所述 n个第一输出相位进行差分运算, 得到 n个第二频率信息;
分别对所述 n个第二频率信息进行低通滤波处理, 得到 n个第二子估计频偏。
5、根据权利要求 1-4任一项所述的方法, 其特征在于, 所述根据所述第二输出相位获取 第二估计频偏值包括:
对所述第二输出相位进行差分运算, 得到第三频率信息;
对所述第三频率信息进行低通滤波处理, 得到第二估计频偏值。
6、根据权利要求 1-5任一项所述的方法, 其特征在于, 所述根据所述 n个第一估计频偏 值和所述第二估计频偏值对所述 n路第二信号进行频偏校正包括:
当解码运算是线性运算时, 对所述第二估计频偏值进行增益控制处理, 将所述增益控制 处理后的第二估计频偏值与所述 n个第一估计频偏值进行合并, 得到 n路所述第一信号对应 的 n个第三估计频偏值;
对所述 n个第三估计频偏值分别进行预处理, 分别判断所述预处理后的 n个第三估计频 偏值是否收敛, 如果是, 分别对所述预处理后的 n个第三估计频偏值进行积分运算, 得到 n 个估计相位信息; 根据所述 n个估计相位信息对所述 n路第二信号进行调相, 得到无频偏信 号。
7、根据权利要求 6所述的方法, 其特征在于, 所述对所述 n个第三估计频偏值分别进行 预处理包括:
将所述 n个第三估计频偏值分别与预设步长相乘, 得到加权后的 n个第四估计频偏值; 将所述 n个第四估计频偏值与对应本地存储的 n个第五估计频偏值进行迭代, 得到迭代 后的 n个第三估计频偏值;
所述分别判断所述预处理后的 n个第三估计频偏值是否收敛包括:
分别判断所述 n个第四估计频偏值是否小于或等于预设阈值, 其中若所述 n个第四估计 频偏值分别小于或等于所述预设阈值, 则表示所述迭代后的 n个第三估计频偏值收敛; 若所 述 n个第四估计频偏值分别大于所述预设阈值, 则表示所述迭代后的 n个第三估计频偏值不 收敛。
8、根据权利要求 1-5任一项所述的方法, 其特征在于, 所述根据所述 n个第一估计频偏 值和所述第二估计频偏值对所述 n路第二信号进行频偏校正包括:
当解码运算不是线性运算时, 对所述 n个第一估计频偏值分别进行预处理, 分别判断所 述预处理后的 n个第一估计频偏值是否收敛, 如果是, 根据所述预处理后的 n个第一估计频 偏值分别对所述 n路第二信号进行频偏校正, 得到第一校正信号; 根据所述第二估计频偏值 对解码处理后的所述第一校正信号进行频偏校正, 得到无频偏信号。
9、 一种计算机程序产品, 其特征在于, 包括计算机程序代码, 当一个计算机单元执行所 述计算机程序代码时, 所述计算机单元执行如任一项权利要求 1-8所记载的动作。
10、 一种分布式多输入多输出 MIM0系统中的频偏校正装置, 其特征在于, 包括: 接收器, 用于接收 n路第一信号, n为正整数;
处理器, 用于对所述 n路第一信号进行频偏校正处理, 得到 n路第一校正信号; 获取单元, 用于获取所述 n路第一校正信号对应的空时均衡器的 n个中心抽头系数、 所 述 n路第一校正信号对应的锁相环鉴相器的 n个第一输出相位和叠加信号对应的锁相环鉴相 器的第二输出相位, 其中所述叠加信号为所述 n路第一校正信号逐一叠加后得到的信号; 第一估计获取单元, 用于根据所述 n个中心抽头系数和所述 n个第一输出相位获取 n个 第一估计频偏值;
第二估计获取单元, 用于根据所述第二输出相位获取第二估计频偏值;
接收校正单元, 用于接收 n路第二信号, 根据所述 n个第一估计频偏值和所述第二估计 频偏值对所述 n路第二信号进行频偏校正。
11、 根据权利要求 10所述的装置, 其特征在于, 所述第一估计获取单元包括: 第一获取子单元, 用于根据所述 n个中心抽头系数获取 n个第一子估计频偏; 第二获取子单元, 用于根据所述 n个第一输出相位获取 n个第二子估计频偏; 处理子单元, 用于将所述 n个第一子估计频偏与对应的 n个第二子估计频偏进行增益控 制和叠加合成处理, 得到 n个第一估计频偏值。
12、 根据权利要求 11所述的装置, 其特征在于, 所述第一获取子单元包括: 相位提取子单元, 用于分别提取所述 n个中心抽头系数的瞬时相位信息, 得到 n个瞬时 相位信息;
第一差分子单元, 用于分别对所述 n个瞬时相位信息进行差分运算, 得到 n个第一频率 信息;
限幅子单元, 用于分别对所述 n个第一频率信息进行限幅处理, 得到 n个限幅后的第一 频率信息;
第一低通滤波子单元, 用于分别对所述 n个限幅后的第一频率信息进行低通滤波处理, 得到 n个第一子估计频偏。
13、 根据权利要求 11或 12所述的装置, 其特征在于, 所述第二获取子单元包括: 第二差分子单元, 用于分别对所述 n个第一输出相位进行差分运算, 得到 n个第二频率 信息;
第二低通滤波子单元, 用于分别对所述 n个第二频率信息进行低通滤波处理, 得到 n个 第二子估计频偏。
14、根据权利要求 10-13任一项所述的装置, 其特征在于, 所述第二估计获取单元包括: 第三差分子单元, 用于对所述第二输出相位进行差分运算, 得到第三频率信息; 第三低通滤波子单元, 用于对所述第三频率信息进行低通滤波处理, 得到第二估计频偏 值。
15、 根据权利要求 10-14任一项所述的装置, 其特征在于, 所述接收校正单元包括: 第三获取子单元, 用于当解码运算是线性运算时, 对所述第二估计频偏值进行增益控制 处理, 将所述增益控制处理后的第二估计频偏值与所述 n个第一估计频偏值进行合并, 得到 n路所述第一信号对应的 n个第三估计频偏值;
第一判断校正子单元, 用于对所述 n个第三估计频偏值分别进行预处理, 分别判断所述 预处理后的 n个第三估计频偏值是否收敛, 如果是, 分别对所述预处理后的 n个第三估计频 偏值进行积分运算, 得到 n个估计相位信息; 根据所述 n个估计相位信息对所述 n路第二信 号进行调相, 得到无频偏信号。
16、 根据权利要求 15所述的装置, 其特征在于, 所述第一判断校正子单元包括: 加权子单元, 用于将所述 n个第三估计频偏值分别与预设步长相乘, 得到加权后的 n个 第四估计频偏值;
迭代子单元, 用于将所述 n个第四估计频偏值与对应本地存储的 n个第五估计频偏值进 行迭代, 得到迭代后的 n个第三估计频偏值;
判断子单元, 用于分别判断所述 n个第四估计频偏值是否小于或等于预设阈值, 其中若 所述 n个第四估计频偏值分别小于或等于所述预设阈值, 则表示所述迭代后的 n个第三估计 频偏值收敛; 若所述 n个第四估计频偏值分别大于所述预设阈值, 则表示所述迭代后的 n个 第三估计频偏值不收敛。
17、 根据权利要求 10-14任一项所述的装置, 其特征在于, 所述接收校正单元包括: 第二判断校正子单元, 用于当解码运算不是线性运算时, 对所述 n个第一估计频偏值分 别进行预处理, 分别判断所述预处理后的 n个第一估计频偏值是否收敛, 如果是, 根据所述 预处理后的 n个第一估计频偏值分别对所述 n路第二信号进行频偏校正,得到第一校正信号; 根据所述第二估计频偏值对解码处理后的所述第一校正信号进行频偏校正,得到无频偏信号。
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201280000641.6A CN102783107B (zh) | 2012-05-23 | 2012-05-23 | 一种频偏校正方法及装置 |
EP12759967.8A EP2621138A4 (en) | 2012-05-23 | 2012-05-23 | METHOD AND DEVICE FOR CORRECTING FREQUENCY OFFSET |
PCT/CN2012/075936 WO2012126429A2 (zh) | 2012-05-23 | 2012-05-23 | 一种频偏校正方法及装置 |
US13/896,020 US8761238B2 (en) | 2012-05-23 | 2013-05-16 | Method and apparatus for correcting frequency offset |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/CN2012/075936 WO2012126429A2 (zh) | 2012-05-23 | 2012-05-23 | 一种频偏校正方法及装置 |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/896,020 Continuation US8761238B2 (en) | 2012-05-23 | 2013-05-16 | Method and apparatus for correcting frequency offset |
Publications (2)
Publication Number | Publication Date |
---|---|
WO2012126429A2 true WO2012126429A2 (zh) | 2012-09-27 |
WO2012126429A3 WO2012126429A3 (zh) | 2013-05-02 |
Family
ID=46879805
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/CN2012/075936 WO2012126429A2 (zh) | 2012-05-23 | 2012-05-23 | 一种频偏校正方法及装置 |
Country Status (4)
Country | Link |
---|---|
US (1) | US8761238B2 (zh) |
EP (1) | EP2621138A4 (zh) |
CN (1) | CN102783107B (zh) |
WO (1) | WO2012126429A2 (zh) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN113141196A (zh) * | 2020-01-20 | 2021-07-20 | 华为技术有限公司 | 一种信道补偿方法及通信装置 |
Families Citing this family (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103095614B (zh) * | 2013-01-24 | 2015-06-24 | 电子科技大学 | 一种突发相干光纤通信中的联合均衡和频偏估计装置 |
CN104639479B (zh) * | 2015-02-03 | 2019-02-26 | 大唐移动通信设备有限公司 | 一种频偏校准方法及设备 |
CN106411806A (zh) * | 2016-08-30 | 2017-02-15 | 华为技术有限公司 | Fb脉冲序列搜索方法及装置 |
CN106549720A (zh) * | 2016-10-13 | 2017-03-29 | 广东欧珀移动通信有限公司 | 一种改善移动终端射频频偏的方法和移动终端 |
CN106603452B (zh) * | 2017-02-23 | 2019-12-10 | 武汉米风通信技术有限公司 | 基于多通道通信接收系统的定时采样与频偏校正方法 |
CN111381075B (zh) * | 2020-04-16 | 2020-12-11 | 华中科技大学 | 一种利用预拟合锁相频差值获取频率偏移量的方法及装置 |
CN114389926A (zh) * | 2020-10-22 | 2022-04-22 | 南京中兴软件有限责任公司 | 系数设置方法、信号处理方法、装置、设备及存储介质 |
CN117155498B (zh) * | 2023-10-30 | 2024-03-22 | 武汉能钠智能装备技术股份有限公司 | 一种针对分布式接收机的信道联合参数处理方法及装置 |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4864286B2 (ja) * | 2001-06-22 | 2012-02-01 | トムソン ライセンシング | 搬送周波数オフセットを補償する方法およびシステム |
US7545891B1 (en) * | 2004-03-09 | 2009-06-09 | Ralink Technology, Inc. | Carrier recovery architectures for multi input multi output orthogonal frequency division multiplexing receivers |
CN1317830C (zh) * | 2005-04-15 | 2007-05-23 | 展讯通信(上海)有限公司 | 自动频偏校正方法及使用该方法的装置和接收机 |
US7738357B2 (en) * | 2005-06-17 | 2010-06-15 | Broadcom Corporation | Apparatus and method for carrier frequency offset estimation and correction in a wireless communication system |
US7177374B2 (en) * | 2005-06-17 | 2007-02-13 | Broadcom Corporation | Apparatus and method for sampling frequency offset estimation and correction in a wireless communication system |
US7856068B1 (en) * | 2005-06-28 | 2010-12-21 | Ralink Technology Corporation | Nested preamble for multi input multi output orthogonal frequency division multiplexing |
US7646823B2 (en) * | 2006-10-30 | 2010-01-12 | Broadcom Corporation | MIMO channel estimation in presence of sampling frequency offset |
US20080101497A1 (en) * | 2006-10-30 | 2008-05-01 | Broadcom Corporation, A California Corporation | MIMO phase noise estimation and correction |
US7813442B2 (en) * | 2006-10-30 | 2010-10-12 | Broadcom Corporation | MIMO channel estimation in presence of carrier frequency offset |
CN1964341B (zh) * | 2006-11-14 | 2011-04-27 | 北京邮电大学 | 多入多出-正交频分复用系统的接收端的频偏估计方法 |
-
2012
- 2012-05-23 CN CN201280000641.6A patent/CN102783107B/zh active Active
- 2012-05-23 EP EP12759967.8A patent/EP2621138A4/en not_active Withdrawn
- 2012-05-23 WO PCT/CN2012/075936 patent/WO2012126429A2/zh active Application Filing
-
2013
- 2013-05-16 US US13/896,020 patent/US8761238B2/en active Active
Non-Patent Citations (2)
Title |
---|
None |
See also references of EP2621138A4 |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN113141196A (zh) * | 2020-01-20 | 2021-07-20 | 华为技术有限公司 | 一种信道补偿方法及通信装置 |
Also Published As
Publication number | Publication date |
---|---|
CN102783107A (zh) | 2012-11-14 |
CN102783107B (zh) | 2015-01-21 |
US8761238B2 (en) | 2014-06-24 |
EP2621138A4 (en) | 2014-01-08 |
US20130315293A1 (en) | 2013-11-28 |
WO2012126429A3 (zh) | 2013-05-02 |
EP2621138A2 (en) | 2013-07-31 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
WO2012126429A2 (zh) | 一种频偏校正方法及装置 | |
CN107769841B (zh) | 高动态极低信噪比下卫星通信Turbo码迭代解调方法 | |
EP2860931B1 (en) | Iterative phase noise tracking and mitigation in wireless communication systems | |
US8638260B2 (en) | Transmitter beamforming steering matrix processing and storage | |
US8199851B1 (en) | Systems and methods for increasing communications bandwidth using non-orthogonal polarizations | |
US9401826B2 (en) | Signal processing unit employing a blind channel estimation algorithm and method of operating a receiver apparatus | |
US8838051B1 (en) | Transmitter beamforming power control | |
WO2000016500A1 (en) | Method for reference signal generation in the presence of frequency offsets in a communications station with spatial processing | |
WO2012117374A1 (en) | Coherent and self - coherent signal processing techniques | |
KR101411086B1 (ko) | 수신 장치 및 방법 | |
US8817902B2 (en) | Receiving device, signal processing device, and signal processing method | |
RU2650179C2 (ru) | Устройство связи, устройство демодуляции, устройство восстановления несущей, устройство компенсации фазовой ошибки, способ компенсации фазовой ошибки и запоминающий носитель, на котором сохранена программа компенсации фазовой ошибки | |
US7630433B2 (en) | Channel estimation enhanced LMS equalizer | |
US20180019835A1 (en) | Mimo demodulating apparatus and method, and line-of-sight wireless communications system | |
EP2491670B1 (en) | System and method for multiple input, multiple output (mimo) communications | |
US8982982B2 (en) | Joint carrier recovery for MIMO systems | |
US8868019B2 (en) | Forward filter training scheme | |
Avram et al. | Quantize and forward cooperative communication: Joint channel and frequency offset estimation | |
JP2004343585A (ja) | 受信装置および方法 | |
WO2008076682A2 (en) | Scaling to reduce wireless signal detection complexity | |
JP2009118276A (ja) | 周波数オフセット推定装置 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 201280000641.6 Country of ref document: CN |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 12759967 Country of ref document: EP Kind code of ref document: A2 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2012759967 Country of ref document: EP |
|
NENP | Non-entry into the national phase |
Ref country code: DE |