Apparatus and method of multiple antenna receiver combining of high data rate wideband packetized wireless communication signals
First Claim
1. An apparatus for combining of M high data rate wideband packetized OFDM wireless communication signals (“
- M signals”
) to form a combined output signal, wherein at least M receive antennas each receive one of the M signals, wherein each of the M signals includes N frequency bins, and wherein M is an integer greater than or equal to 2 and N is a positive integer, the apparatus comprising;
a joint timing recovery unit that performs joint coarse signal timing estimation and joint frequency offset estimation on digital data corresponding to each of the M signals;
M Fast Fourier Transform (FFT) units that each convert the digital data for one of the M signals into frequency domain information in the form of sub-carrier data for each of N frequency bins for that one M signal and that output the frequency domain information for each of the M signals; and
a combiner that weights and combines the frequency domain information of the M FFT units to thereby generate the combined output signal having reduced circuit impairments and channel effects,wherein the joint timing recovery unit that performs joint timing estimation determines a coarse end time for P consecutive Shorts within the M signals,wherein the joint timing recovery unit determines the coarse end time using self correlation of some of the P Shorts within the M signals,wherein the joint timing recovery unit includes a joint coarse signal time estimation unit that performs the joint coarse signal timing estimation on each of the M signals, the joint coarse signal time estimation unit comprising;
M self-correlation units, wherein each self-correlation unit independently self-correlates the some of the P Shorts in one of the M signals after the automatic gain control unit indicates the start of the M signals and outputs for the one M signal a self correlation signal that is the self-correlation of the P Shorts, wherein P is a positive integer;
M weighting units that weight the self correlation outputs based on the signal strength;
a summer that sums the M weighted self correlation signals to obtain a weighted summed self correlation signal;
a normalizing unit that normalizes the weighted summed self correlation signal, thereby outputting a normalized self correlation signal; and
a coarse timing estimation unit that receives the normalized self correlation signal and obtains, for the M signals, the end time for the P Shorts in the M signals by comparing the normalized self correlation signal power to a threshold.
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Abstract
The present invention provides an apparatus and method of multiple antenna receiver combining of high data rate wideband packetized wireless communication signals, where the apparatus includes M receive antennas, receiving M high data rate wideband packetized wireless communication signals, where each of the signals includes N frequency bins. The apparatus, in an exemplary embodiment, includes (1) a joint timing recovery units that perform joint coarse signal timing estimation, joint frequency offset estimation, and joint fine timing estimation on each of the signals, (2) M Fast Fourier Transform units (FFTs) that each convert the digital data for each of the M signals into frequency domain information for each of the N received frequencies and that output Q pilots for each of the signals, where Q is a positive integer, and (3) a combiner that weights and combines the outputs of the M FFTs for each of the N received frequencies.
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Citations
36 Claims
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1. An apparatus for combining of M high data rate wideband packetized OFDM wireless communication signals (“
- M signals”
) to form a combined output signal, wherein at least M receive antennas each receive one of the M signals, wherein each of the M signals includes N frequency bins, and wherein M is an integer greater than or equal to 2 and N is a positive integer, the apparatus comprising;a joint timing recovery unit that performs joint coarse signal timing estimation and joint frequency offset estimation on digital data corresponding to each of the M signals; M Fast Fourier Transform (FFT) units that each convert the digital data for one of the M signals into frequency domain information in the form of sub-carrier data for each of N frequency bins for that one M signal and that output the frequency domain information for each of the M signals; and a combiner that weights and combines the frequency domain information of the M FFT units to thereby generate the combined output signal having reduced circuit impairments and channel effects, wherein the joint timing recovery unit that performs joint timing estimation determines a coarse end time for P consecutive Shorts within the M signals, wherein the joint timing recovery unit determines the coarse end time using self correlation of some of the P Shorts within the M signals, wherein the joint timing recovery unit includes a joint coarse signal time estimation unit that performs the joint coarse signal timing estimation on each of the M signals, the joint coarse signal time estimation unit comprising; M self-correlation units, wherein each self-correlation unit independently self-correlates the some of the P Shorts in one of the M signals after the automatic gain control unit indicates the start of the M signals and outputs for the one M signal a self correlation signal that is the self-correlation of the P Shorts, wherein P is a positive integer; M weighting units that weight the self correlation outputs based on the signal strength; a summer that sums the M weighted self correlation signals to obtain a weighted summed self correlation signal; a normalizing unit that normalizes the weighted summed self correlation signal, thereby outputting a normalized self correlation signal; and a coarse timing estimation unit that receives the normalized self correlation signal and obtains, for the M signals, the end time for the P Shorts in the M signals by comparing the normalized self correlation signal power to a threshold. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
- M signals”
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22. An apparatus for combining of M high data rate wideband packetized OFDM wireless communication signals (“
- M signals”
) to form a combined output signal, wherein at least M receive antennas each receive one of the M signals, wherein each of the M signals includes N frequency bins, and wherein M is an integer greater than or equal to 2 and N is a positive integer, the apparatus comprising;a joint timing recovery unit that performs joint coarse signal timing estimation and joint frequency offset estimation on digital data corresponding to each of the M signals; M Fast Fourier Transform (FFT) units that each convert the digital data for one of the M signals into frequency domain information in the form of sub-carrier data for each of N frequency bins for that one M signal and that output the frequency domain information for each of the M signals; and a combiner that weights and combines the frequency domain information of the M FFT units to thereby generate the combined output signal having reduced circuit impairments and channel effects, wherein the joint timing recovery unit that performs joint timing estimation determines a coarse end time for P consecutive Shorts within the M signals, wherein the joint timing recovery unit determines the coarse end time using cross correlation of some of the P Shorts within each of the M signals with a known Short sequence, followed by self correlation of the corresponding cross correlation outputs, wherein the joint timing recovery unit includes a joint coarse signal time estimation unit that performs the joint coarse signal timing estimation on each of the M signals, the joint coarse signal time estimation unit further comprises; M cross-correlation units, wherein each cross-correlation unit independently cross-correlates some of the P Shorts in one of the M signals with a known Short sequence, after the automatic gain control unit indicates the start of the M signals and outputs for each of the M signals a cross-correlation signal; M self-correlation units, wherein each self-correlation unit is logically coupled to a separate one of the M cross-correlation units and wherein each self-correlation unit independently self-correlates the output of the corresponding cross-correlation unit; M weighting units that weight the self correlation outputs based on the signal strength; a summer that sums the M weighted self correlation signals to obtain a weighted summed self correlation signal; a normalizing unit that normalizes the weighted summed self correlation signal, thereby outputting a normalized self correlation signal; and a coarse timing estimation unit that receives the normalized self correlation signal and obtains, for the M signals, the end time for the P Shorts in the M signals by comparing the normalized self correlation signal power to a threshold. - View Dependent Claims (23)
- M signals”
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24. An apparatus for combining of M high data rate wideband packetized OFDM wireless communication signals (“
- M signals”
) to form a combined output signal, wherein at least M receive antennas each receive one of the M signals, wherein each of the M signals includes N frequency bins, and wherein M is an integer greater than or equal to 2 and N is a positive integer, the apparatus comprising;a joint timing recovery unit that performs joint coarse signal timing estimation and joint frequency offset estimation on digital data corresponding to each of the M signals; M Fast Fourier Transform (FFT) units that each convert the digital data for one of the M signals into frequency domain information in the form of sub-carrier data for each of N frequency bins for that one M signal and that output the frequency domain information for each of the M signals; and a combiner that weights and combines the frequency domain information of the M FFT units to thereby generate the combined output signal having reduced circuit impairments and channel effects, wherein the joint timing recovery unit determines a weighted frequency offset for the M signals, wherein the joint timing recovery unit comprises a joint frequency offset estimation unit that performs the joint frequency offset estimation on the M signals, the joint frequency offset estimation unit comprising; M self-correlation units, wherein each self-correlation unit independently self-correlates some of the P Shorts in each of the M signals and outputs a self-correlation signal that is the self-correlation output of the some of the P Shorts, wherein P is a positive integer; M weighting units that weight the self correlation outputs based on the signal strength; a summer that sums the M weighted self-correlation signals, thereby obtaining a summed self-correlation signal; a normalizing unit that normalizes the weighted summed self correlation signal, thereby outputting a normalized self correlation signal; an angle calculator that extracts an angle from the normalized self-correlation signal; and a coarse frequency offset estimation unit that obtains the frequency offset using the angle. - View Dependent Claims (25)
- M signals”
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26. An apparatus for combining of M high data rate wideband packetized OFDM wireless communication signals (“
- M signals”
) to form a combined output signal, wherein at least M receive antennas each receive one of the M signals, wherein each of the M signals includes N frequency bins, and wherein M is an integer greater than or equal to 2 and N is a positive integer, the apparatus comprising;a joint timing recovery unit that performs joint coarse signal timing estimation and joint frequency offset estimation on digital data corresponding to each of the M signals; M Fast Fourier Transform (FFT) units that each convert the digital data for one of the M signals into frequency domain information in the form of sub-carrier data for each of N frequency bins for that one M signal and that output the frequency domain information for each of the M signals; and a combiner that weights and combines the frequency domain information of the M FFT units to thereby generate the combined output signal having reduced circuit impairments and channel effects, wherein the joint timing recovery unit determines a weighted frequency offset for the M signals, wherein the joint timing recovery unit comprises a joint frequency offset estimation unit that performs the joint frequency offset estimation on each of the M signals, the joint frequency offset estimation unit comprising; M cross-correlation units, wherein each cross-correlation unit independently cross-correlates some of the P Shorts in one of the M signals with a known Short sequence, after the automatic gain control unit indicates the start of the one M signal and outputs for the one M signal a cross-correlation signal; M self-correlation units, wherein each self-correlation unit is logically coupled to a separate one of the M cross-correlation units and wherein each self-correlation unit independently self-correlates the output of the corresponding cross-correlation output; M weighting units that weight the self correlation outputs based on the signal strength; a summer that sums the M weighted self-correlation signals, thereby obtaining a weighted summed self-correlation signal; a normalizing unit that normalizes the weighted summed self correlation signal, thereby outputting a normalized self correlation signal; an angle calculator that extracts an angle from the normalized self-correlation signal; and a coarse frequency offset estimation unit that obtains the frequency offset using the angle.
- M signals”
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27. An apparatus for combining of M high data rate wideband packetized OFDM wireless communication signals (“
- M signals”
) to form a combined output signal, wherein at least M receive antennas each receive one of the M signals, wherein each of the M signals includes N frequency bins, and wherein M is an integer greater than or equal to 2 and N is a positive integer, the apparatus comprising;a joint timing recovery unit that performs joint coarse signal timing estimation and joint frequency offset estimation on digital data corresponding to each of the M signals; M Fast Fourier Transform (FFT) units that each convert the digital data for one of the M signals into frequency domain information in the form of sub-carrier data for each of N frequency bins for that one M signal and that output the frequency domain information for each of the M signals; and a combiner that weights and combines the frequency domain information of the M FFT units to thereby generate the combined output signal having reduced circuit impairments and channel effects, wherein the joint timing recovery unit determines a weighted frequency offset for the M signals, wherein the joint timing recovery unit comprises a joint frequency offset estimation unit that performs the joint frequency offset estimation on the M signals, the joint frequency offset estimation unit comprising; M self-correlation units, wherein each self-correlation unit independently self-correlates some of the P Shorts in each of the M signals and outputs a self-correlation signal that is the self-correlation output of the some of the P Shorts, wherein P is a positive integer; M weighting units that weight the self correlation outputs based on the signal strength; a summer that sums the M weighted self-correlation signals, thereby obtaining a summed self-correlation signal; an angle calculator that extracts an angle from the weighted summed self correlation signal; and a coarse frequency offset estimation unit that obtains the frequency offset using the angle.
- M signals”
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28. An apparatus for combining of M high data rate wideband packetized OFDM wireless communication signals (“
- M signals”
) to form a combined output signal, wherein at least M receive antennas each receive one of the M signals, wherein each of the M signals includes N frequency bins, and wherein M is an integer greater than or equal to 2 and N is a positive integer, the apparatus comprising;a joint timing recovery unit that performs joint coarse signal timing estimation and joint frequency offset estimation on digital data corresponding to each of the M signals; M Fast Fourier Transform (FFT) units that each convert the digital data for one of the M signals into frequency domain information in the form of sub-carrier data for each of N frequency bins for that one M signal and that output the frequency domain information for each of the M signals; and a combiner that weights and combines the frequency domain information of the M FFT units to thereby generate the combined output signal having reduced circuit impairments and channel effects, wherein the joint timing recovery unit determines a weighted frequency offset for the M signals, wherein the joint timing recovery unit comprises a joint frequency offset estimation unit that performs the joint frequency offset estimation on each of the M signals, the joint frequency offset estimation unit comprising; M cross-correlation units, wherein each cross-correlation unit independently cross-correlates some of the P Shorts in one of the M signals with a known Short sequence, after the automatic gain control unit indicates the start of the one M signal and outputs for the one M signal a cross-correlation signal; M self-correlation units, wherein each self-correlation unit is logically coupled to a separate one of the M cross-correlation units and wherein each self-correlation unit independently self-correlates the output of the corresponding cross-correlation output; M weighting units that weight the self correlation outputs based on the signal strength; a summer that sums the M weighted self-correlation signals, thereby obtaining a weighted summed self-correlation signal; an angle calculator that extracts an angle from the weighted summed self correlation signal; and a coarse frequency offset estimation unit that obtains the frequency offset using the angle.
- M signals”
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29. An apparatus for combining of M high data rate wideband packetized OFDM wireless communication signals (“
- M signals”
) to form a combined output signal, wherein at least M receive antennas each receive one of the M signals, wherein each of the M signals includes N frequency bins, and wherein M is an integer greater than or equal to 2 and N is a positive integer, the apparatus comprising;a joint timing recovery unit that performs joint coarse signal timing estimation and joint frequency offset estimation on digital data corresponding to each of the M signals; M Fast Fourier Transform (FFT) units that each convert the digital data for one of the M signals into frequency domain information in the form of sub-carrier data for each of N frequency bins for that one M signal and that output the frequency domain information for each of the M signals; and a combiner that weights and combines the frequency domain information of the M FFT units to thereby generate the combined output signal having reduced circuit impairments and channel effects, wherein the joint timing recovery unit determines a weighted frequency offset for the M signals, wherein the combiner comprises; a channel estimation unit (CEU) that, for each of the N frequency bins in each of the M signals, receives the outputs of the M FFFs and outputs a channel estimate; a weight calculator that, for each of the N frequency bins in each of the M signals, receives a corresponding one of the channel estimates from the CEU, receives M RF gains, provides feedback to the CEU, and outputs a weight; M weight blocks that, for each of the N frequency bins in each of the M signals, receive the weights from the weight calculator, receive sub-carrier data for each of the N frequency bins for each of the M signals, and multiply the sub-carrier data for each of the N frequency bins for each of the M signals with a corresponding weight to obtain weighted sub-carrier data for each of the N frequency bins for each of the M signals; a summer that sums the weighted sub-carrier data by frequency bin to obtain M weighted sub-carrier data sums; a pilot tracking unit that, for each of the N frequency bins, receives pilot data from a corresponding pilot frequency bin also output from the summer and outputs pilot tracking information for each of the N frequency bins; and a channel correction unit that, for each of the N frequency bins, converts the weights from the weight calculator, the corresponding weighted sub-carrier data stun output from the summer, and the pilot tracking information from the pilot tracking unit into the combined output signal. - View Dependent Claims (30, 31, 32, 33, 34, 35, 36)
- M signals”
Specification