Rake receiver with selective ray combining

Claim 2

In a spread spectrum communications system wherein a transmitter transmits a data signal to a receiver, said receiver comprising: means for receiving at least two rays of the data signal, wherein the receiving means produces in-phase (I) and quadrature (Q) components for each ray; means for sampling said I and Q components to produce at least one I sample and at least one Q sample for each ray; means for selecting at least two wrays of said samples, each wray including I samples or Q samples from any one of said rays; and means for combining said samples in each of said selected wrays to recover the transmitted data signal.

Claim 3

In a code division multiple access system for communicating a sequence of data symbols to a receiver, wherein a transmitter combines each data symbol with a known code sequence to form a respective transmitted symbol, said receiver comprising: means for receiving a composite signal of overlapping modulated carrier signals including at least two rays and for demodulating the composite signal to recover the transmitted symbols in each ray, the receiving and demodulating means producing in-phase (I) and quadrature (Q) components for each ray; means for sampling said I and Q components to produce at least one I sample and at least one Q sample for each transmitted symbol; means for selecting at least two wrays of said samples, each wray including I samples or Q samples from any one of said rays; means for correlating said samples in each of said selected wrays to a known code sequence and generating correlation values; means for combining said correlation values to generate a combined value; and means for comparing said combined value with a threshold to determine each data symbol corresponding to each transmitted symbol.

Claim 4

In a code division multiple access system for communicating a sequence of data symbols to a receiver, wherein a transmitter combines each data symbol with a known code sequence to form a respective transmitted symbol, said receiver comprising: means for receiving a composite signal of overlapping modulated carrier signals including at least two rays and for demodulating the composite signal to recover the transmitted symbols in each ray, the receiving and demodulating means producing in-phase (I) and quadrature (Q) components for each ray; means for sampling said I and Q components to produce at least one I sample and at least one Q sample for each transmitted symbol; means for selecting at least two wrays of said samples, each wray including I samples or Q samples from any one of said rays; means for correlating said samples in each of said selected wrays to a known code sequence and generating correlation values; means for combining said correlation values to generate a combined value; and means for comparing said combined value with a threshold to determine each data symbol corresponding to each transmitted symbol.

Claim 5

The system according to claim 2 wherein said selecting means selects said samples from two different wrays, a first wray including I samples from one of said rays and a second wray including Q samples from one of said rays.

Claim 6

The system according to claim 2 wherein the combining means includes: means for multiplying each correlation value by a corresponding weight to produce a plurality of weighted values; and means for summing the weighted values to generate said combined value.

Claim 7

The system according to claim 2 wherein the correlation means includes a single complex correlator for correlating each selected wray with said known code sequence.

Claim 8

The system according to claim 2 wherein the correlation means includes a single scalar correlator for correlating each selected wray with said known code sequence.

Claim 9

The system according to claim 2 wherein the correlation means includes a plurality of complex correlators for correlating each selected wray with said known code sequence.

Claim 10

The system according to claim 2 wherein the correlation means includes a plurality of scalar correlators for correlating each selected wray with said known code sequence.

Claim 11

In a code division multiple access system for communicating a sequence of data symbols to a receiver, wherein a transmitter combines each data symbol with a known code sequence to form a respective transmitted symbol, said receiver comprising: means for receiving a composite signal of overlapping modulated carrier signals including at least two rays and for demodulating the composite signal to recover the transmitted symbols in each ray, the receiving and demodulating means producing in-phase (I) and quadrature (Q) components for each ray; means for sampling said I and Q components to produce at least one I sample and at least one Q sample for each transmitted symbol; means for selecting at least two wrays of said samples, each wray including I samples or Q samples from any one of said rays; means for combining said samples in each of said selected wrays to generate groups of combined samples; means for correlating said groups of combined samples with a known code sequence and generating a correlation value; and means for comparing said correlation value with a threshold to determine each data symbol corresponding to each transmitted symbol.

Claim 12

In a code division multiple access system for communicating a sequence of data symbols to a receiver, wherein a transmitter combines each data symbol with a known code sequence to form a respective transmitted symbol, said receiver comprising: means for receiving a composite signal of overlapping modulated carrier signals including at least two rays and for demodulating the composite signal to recover the transmitted symbols in each ray, the receiving and demodulating means producing in-phase (I) and quadrature (Q) components for each ray; means for sampling said I and Q components to produce at least one I sample and at least one Q sample for each transmitted symbol; means for selecting at least two wrays of said samples, each wray including I samples or Q samples from any one of said rays; means for combining said samples in each of said selected wrays to generate groups of combined samples; means for correlating said groups of combined samples with a known code sequence and generating a correlation value; and means for comparing said correlation value with a threshold to determine each data symbol corresponding to each transmitted symbol.

Claim 13

The system according to claim 9 wherein said selecting means selects said samples from two different wrays, a first wray including I samples from one of said rays and a second wray including Q samples from one of said rays.

Claim 14

The system according to claim 9 wherein the combining means includes: means for multiplying each sample by a corresponding weight to produce a plurality of weighted values; and means for summing the weighted values to generate said groups of combined samples.

Claim 15

The system according to claim 11 wherein the multiplying means includes a single complex sample-by-sample multiplier for multiplying each sample by said corresponding weight.

Claim 16

The system according to claim 11 wherein the multiplying means includes a single scalar sample-by-sample multiplier for multiplying each sample by said corresponding weight.

Claim 17

The system according to claim 11 wherein the multiplying means includes a plurality of complex sample-by-sample multipliers for multiplying each sample by said corresponding weight.

Claim 18

The system according to claim 11 wherein the multiplying means includes a plurality of scalar sample by sample multipliers for multiplying each sample by said corresponding weight.

Claim 19

In a code division multiple access system for communicating data symbols to a receiver, wherein a transmitter maps a stream of data symbols into a stream of code symbols and further combines each code symbol with one scrambling bit sequence to form a stream of respective transmitted scrambled code symbols, the receiver comprising: means for receiving a composite signal of overlapping modulated carrier signals including at least two rays and for demodulating the composite signal to recover the transmitted scrambled code symbols in each ray, the receiving and demodulating means producing in-phase (I) and quadrature (Q) components for each ray; means for sampling the I and Q components to produce at least one I sample and at least one Q sample for each transmitted scrambled code symbol; means for successively selecting at least two wrays of said samples, each wray including I samples or Q samples from any one of said rays; means for successively descrambling each wray of samples with the scrambling bit sequence; means for successively correlating the descrambled samples in the selected wrays with a set of known code sequences and generating correlation values; means for successively combining said correlation values to generate combined values; and means for successively comparing the combined values with each other to detect each transmitted scrambled code symbol, said detected scrambled code symbols corresponding to said stream of data symbols.

Claim 20

In a code division multiple access system for communicating data symbols to a receiver, wherein a transmitter maps a stream of data symbols into a stream of code symbols and further combines each code symbol with one scrambling bit sequence to form a stream of respective transmitted scrambled code symbols, the receiver comprising: means for receiving a composite signal of overlapping modulated carrier signals including at least two rays and for demodulating the composite signal to recover the transmitted scrambled code symbols in each ray, the receiving and demodulating means producing in-phase (I) and quadrature (Q) components for each ray; means for sampling the I and Q components to produce at least one I sample and at least one Q sample for each transmitted scrambled code symbol; means for successively selecting at least two wrays of said samples, each wray including I samples or Q samples from any one of said rays; means for successively descrambling each wray of samples with the scrambling bit sequence; means for successively correlating the descrambled samples in the selected wrays with a set of known code sequences and generating correlation values; means for successively combining said correlation values to generate combined values; and means for successively comparing the combined values with each other to detect each transmitted scrambled code symbol, said detected scrambled code symbols corresponding to said stream of data symbols.

Claim 21

The system according to claim 16 wherein said selecting means successively selects said samples from two different wrays, a first wray including I samples from one of said rays and a second wray including Q samples from one of said rays.

Claim 22

The system according to claim 16 further including: means for successively removing a selected one of said code symbols corresponding to the detected one of said code symbols from the composite signal to generate a residual composite signal; and means for successively reconstructing the original composite signal samples less the selected code symbol from the residual composite signal and transmitting the samples to the selecting means.

Claim 23

The system according to claim 18 wherein said reconstructing means further includes: means for inverse correlating the residual composite signal; and means for rescrambling the residual composite signal to reconstruct the original composite signal without the code symbol corresponding to the detected code symbol using said scrambling bit sequence.

Claim 24

The system according to claim 19 wherein said correlating means includes means for computing a fast Walsh transform to correlate the samples to known Walsh-Hadamard sequences and said inverse correlating means includes means for computing an inverse fast Walsh transform to reconstruct samples of the residual composite signal.

Claim 25

The system according to claim 18 wherein said comparing means determines which combined value is the largest, and said removing means removes the code symbol, corresponding to the largest correlation value, from the composite signal to form the residual composite signal.

Claim 26

The system according to claim 16 wherein the correlation means includes means for computing a fast Walsh transform to correlate the samples to known Walsh-Hadamard sequences.

Claim 27

A system according to claim 16 wherein said set of known code sequences are code words from an orthogonal block code.

Claim 28

A system according to claim 16 wherein said set of known code sequences are code words from a bi-orthogonal block code.

Claim 29

In a code division multiple access system for communicating data symbols to a receiver, wherein a transmitter maps a stream of data symbols into a stream of code symbols and further combines each code symbol with one scrambling bit sequence to form a stream of respective transmitted scrambled code symbols, the receiver comprising: means for receiving a composite signal of overlapping modulated carrier signals including at least two rays and for demodulating the composite signal to recover the transmitted scrambled code symbols in each ray, the receiving and demodulating means producing in-phase (I) and quadrature (Q) components for each ray; means for sampling the I and Q components to produce at least one I sample and at least one Q sample for each transmitted scrambled code symbol; means for successively selecting at least two wrays of said samples, each wray including I samples or Q samples from any one of said rays; means for successively descrambling each wray of samples with the scrambling bit sequence; means for successively combining said descrambled wrays of samples to generate groups of combined samples; and means for successively correlating said groups of combined samples with a set of known code sequences and generating a plurality of correlation values, one for each sequence; and means for successively comparing the correlation values with each other to detect each transmitted scrambled code symbol, said detected scrambled code symbols corresponding to said stream of data symbols.

Claim 30

In a code division multiple access system for communicating data symbols to a receiver, wherein a transmitter maps a stream of data symbols into a stream of code symbols and further combines each code symbol with one scrambling bit sequence to form a stream of respective transmitted scrambled code symbols, the receiver comprising: means for receiving a composite signal of overlapping modulated carrier signals including at least two rays and for demodulating the composite signal to recover the transmitted scrambled code symbols in each ray, the receiving and demodulating means producing in-phase (I) and quadrature (Q) components for each ray; means for sampling the I and Q components to produce at least one I sample and at least one Q sample for each transmitted scrambled code symbol; means for successively selecting at least two wrays of said samples, each wray including I samples or Q samples from any one of said rays; means for successively descrambling each wray of samples with the scrambling bit sequence; means for successively combining said descrambled wrays of samples to generate groups of combined samples; and means for successively correlating said groups of combined samples with a set of known code sequences and generating a plurality of correlation values, one for each sequence; and means for successively comparing the correlation values with each other to detect each transmitted scrambled code symbol, said detected scrambled code symbols corresponding to said stream of data symbols.

Claim 31

The system according to claim 25 wherein said selecting means selects said samples from two different wrays, a first wray including I samples from one of said rays and a second wray including Q samples from one of said rays.

Claim 32

The system according to claim 25 wherein the correlation means includes means for computing a fast Walsh transform to correlate the samples to known Walsh-Hadamard sequences.

Claim 33

A system according to claim 25 wherein said set of known code sequences are code words in an orthogonal block code.

Claim 34

A system according to claim 25 wherein said set of known code sequences are code words in a bi-orthogonal block code.

Claim 35

In a code division multiple access system, a method for communicating a sequence of data symbols to a receiver, wherein a transmitter combines each data symbol with a known code sequence to form a respective transmitted symbol, said method comprising the steps of: receiving a composite signal of overlapping modulated carrier signals including at least two rays; demodulating the composite signal to recover the transmitted symbols in each ray, producing in-phase (I) and quadrature (Q) components for each ray; sampling said I and Q components to produce at least one I sample and at least one Q sample for each transmitted symbol; selecting at least two wrays of said samples, each wray including I samples or Q samples from any one of said rays; correlating said samples in each of said selected wrays to a known code sequence and generating correlation values; combining said correlation values to generate a combined value; and comparing said combined value with a threshold to determine each data symbol corresponding to each transmitted symbol.

Claim 36

In a code division multiple access system, a method for communicating a sequence of data symbols to a receiver, wherein a transmitter combines each data symbol with a known code sequence to form a respective transmitted symbol, said method comprising the steps of: receiving a composite signal of overlapping modulated carrier signals including at least two rays; demodulating the composite signal to recover the transmitted symbols in each ray, producing in-phase (I) and quadrature (Q) components for each ray; sampling said I and Q components to produce at least one I sample and at least one Q sample for each transmitted symbol; selecting at least two wrays of said samples, each wray including I samples or Q samples from any one of said rays; correlating said samples in each of said selected wrays to a known code sequence and generating correlation values; combining said correlation values to generate a combined value; and comparing said combined value with a threshold to determine each data symbol corresponding to each transmitted symbol.

Claim 37

The method according to claim 30 wherein said step of selecting includes the step of selecting said samples from two different wrays, a first wray including I samples from one of said rays and a second wray including Q samples from one of said rays.

Claim 38

The method according to claim 30 wherein said step of combining further includes the steps of: multiplying each correlation value by a corresponding weight to produce a plurality of weighted values; and summing the weighted values to generate said combined value.

Claim 39

The method according to claim 30 wherein the step of correlating includes correlating each selected wray with said known code sequence using a single complex correlator.

Claim 40

The method according to claim 30 wherein the step of correlating includes correlating each selected wray with said known code sequence using a single scalar correlator.

Claim 41

The method according to claim 30 wherein the step of correlating includes correlating each selected wray with said known code sequence using a plurality of complex correlators.

Claim 42

The method according to claim 30 wherein the step of correlating includes correlating each selected wray with said known code sequence using a plurality of scalar correlators.

Claim 43

In a code division multiple access system, a method for communicating a sequence of data symbols to a receiver, wherein a transmitter combines each data symbol with a known code sequence to form a respective transmitted symbol, said method comprising the steps of: receiving a composite signal of overlapping modulated carrier signals including at least two rays; demodulating the composite signal to recover the transmitted symbols in each ray, producing in-phase (I) and quadrature (Q) components for each ray; sampling said I and Q components to produce at least one I sample and at least one Q sample for each transmitted symbol; selecting at least two wrays of said samples, each wray including I samples or Q samples from any one of said rays; combining said wrays of samples to generate groups of combined samples; correlating said groups of combined samples with a known code sequence and generating a correlation value; and comparing said correlation value with a threshold to determine each data symbol corresponding to each transmitted symbol.

Claim 44

In a code division multiple access system, a method for communicating a sequence of data symbols to a receiver, wherein a transmitter combines each data symbol with a known code sequence to form a respective transmitted symbol, said method comprising the steps of: receiving a composite signal of overlapping modulated carrier signals including at least two rays; demodulating the composite signal to recover the transmitted symbols in each ray, producing in-phase (I) and quadrature (Q) components for each ray; sampling said I and Q components to produce at least one I sample and at least one Q sample for each transmitted symbol; selecting at least two wrays of said samples, each wray including I samples or Q samples from any one of said rays; combining said wrays of samples to generate groups of combined samples; correlating said groups of combined samples with a known code sequence and generating a correlation value; and comparing said correlation value with a threshold to determine each data symbol corresponding to each transmitted symbol.

Claim 45

The method according to claim 37 wherein said step of selecting includes the step of selecting said samples from two different wrays, a first wray including I samples from one of said rays and a second wray including Q samples from one of said rays.

Claim 46

The method according to claim 37 wherein said step of combining further includes the steps of: multiplying each sample by a corresponding weight to produce a plurality of weighted values; and summing the weighted values to generate said groups of combined samples.

Claim 47

The method according to claim 39 wherein the step of multiplying includes multiplying each sample by said corresponding weight using a single complex sample-by-sample multiplier.

Claim 48

The method according to claim 39 wherein the step of multiplying includes multiplying each sample by said corresponding weight using a single scalar sample-by-sample multiplier.

Claim 49

The method according to claim 39 wherein the step of multiplying includes multiplying each sample by said corresponding weight using a plurality of complex sample-by-sample multipliers.

Claim 50

The method according to claim 39 wherein the step of multiplying includes multiplying each sample by said corresponding weight using a plurality of scalar sample by sample multipliers.

Claim 51

In a code division multiple access system, a method for communicating data symbols to a receiver, wherein a transmitter maps a stream of data symbols into a stream of code symbols and further combines each code symbol with one scrambling bit sequence to form a stream of respective transmitted scrambled code symbols, the method comprising the steps of: receiving a composite signal of overlapping modulated carrier signals including at least two rays and demodulating the composite signal to recover the transmitted scrambled code symbols in each ray, producing in-phase (I) and quadrature (Q) components for each ray; sampling the I and Q components to produce at least one I sample and at least one Q sample for each transmitted scrambled code symbol; successively selecting at least two wrays of said samples, each wray including I samples or Q samples from any one of said rays; successively descrambling each wray of samples with the scrambling bit sequence; successively correlating the descrambled samples in the selected wrays with a set of known code sequences and generating correlation values; successively combining said correlation values to generate combined values; and successively comparing the combined values with each other to detect each transmitted scrambled code symbol, said detected scrambled code symbols corresponding to said stream of data symbols.

Claim 52

In a code division multiple access system, a method for communicating data symbols to a receiver, wherein a transmitter maps a stream of data symbols into a stream of code symbols and further combines each code symbol with one scrambling bit sequence to form a stream of respective transmitted scrambled code symbols, the method comprising the steps of: receiving a composite signal of overlapping modulated carrier signals including at least two rays and demodulating the composite signal to recover the transmitted scrambled code symbols in each ray, producing in-phase (I) and quadrature (Q) components for each ray; sampling the I and Q components to produce at least one I sample and at least one Q sample for each transmitted scrambled code symbol; successively selecting at least two wrays of said samples, each wray including I samples or Q samples from any one of said rays; successively descrambling each wray of samples with the scrambling bit sequence; successively correlating the descrambled samples in the selected wrays with a set of known code sequences and generating correlation values; successively combining said correlation values to generate combined values; and successively comparing the combined values with each other to detect each transmitted scrambled code symbol, said detected scrambled code symbols corresponding to said stream of data symbols.

Claim 53

The method according to claim 44 wherein said step of successively selecting includes the step of successively selecting said samples from two different wrays, a first wray including I samples from one of said rays and a second wray including Q samples from one of said rays.

Claim 54

The method according to claim 44 further including the steps of: successively removing a selected one of said code symbols corresponding to the detected one of said code symbols from the composite signal to generate a residual composite signal; and successively reconstructing the original composite signal samples less the selected code symbol from the residual composite signal and transmitting the samples to the selecting means.

Claim 55

The method according to claim 46 wherein said step of reconstructing further includes: inverse correlating the residual composite signal; and rescrambling the residual composite signal to reconstruct the original composite signal without the code symbol corresponding to the detected code symbol using the scrambling bit sequence.

Claim 56

The method according to claim 47 wherein said step of correlating includes computing a fast Walsh transform to correlate the samples to known Walsh-Hadamard sequences and said step of inverse correlating includes computing an inverse fast Walsh transform to reconstruct samples of the residual composite signal.

Claim 57

The method according to claim 46 wherein said step of comparing determines which combined value is the largest, and said step of removing removes the code symbol corresponding to the largest correlation value from the composite signal to form the residual composite signal.

Claim 58

A method according to claim 44 wherein said set of known code sequences are code words from an orthogonal block code.

Claim 59

A method according to claim 44 wherein said set of known code sequences are code words from a bi-orthogonal block code.

Claim 60

The method according to claim 44 wherein the step of correlating includes computing a fast Walsh transform to correlate the samples to known Walsh-Hadamard sequences.

Claim 61

In a code division multiple access system, a method for communicating data symbols to a receiver, wherein a transmitter maps a stream of data symbols into a stream of code symbols and further combines each code symbol with one scrambling bit sequence to form a stream of respective transmitted scrambled code symbols, the method comprising the steps of: receiving a composite signal of overlapping modulated carrier signals including at least two rays and demodulating the composite signal to recover the transmitted scrambled code symbols in each ray, producing in-phase (I) and quadrature (Q) components for each ray; sampling the I and Q components to produce at least one I sample and at least one Q sample for each transmitted scrambled code symbol; successively selecting at least two wrays of said samples, each wray including I samples or Q samples from any one of said rays; successively descrambling each wray of samples with the scrambling bit sequence; successively combining said descrambled wrays of samples to generate groups of combined samples; successively correlating said groups of combined samples with a set of known code sequences and generating a plurality of correlation values, one for each sequence; and successively comparing the correlation values with each other to detect each transmitted scrambled code symbol, said detected scrambled code symbols corresponding to said stream of data symbols.

Claim 62

In a code division multiple access system, a method for communicating data symbols to a receiver, wherein a transmitter maps a stream of data symbols into a stream of code symbols and further combines each code symbol with one scrambling bit sequence to form a stream of respective transmitted scrambled code symbols, the method comprising the steps of: receiving a composite signal of overlapping modulated carrier signals including at least two rays and demodulating the composite signal to recover the transmitted scrambled code symbols in each ray, producing in-phase (I) and quadrature (Q) components for each ray; sampling the I and Q components to produce at least one I sample and at least one Q sample for each transmitted scrambled code symbol; successively selecting at least two wrays of said samples, each wray including I samples or Q samples from any one of said rays; successively descrambling each wray of samples with the scrambling bit sequence; successively combining said descrambled wrays of samples to generate groups of combined samples; successively correlating said groups of combined samples with a set of known code sequences and generating a plurality of correlation values, one for each sequence; and successively comparing the correlation values with each other to detect each transmitted scrambled code symbol, said detected scrambled code symbols corresponding to said stream of data symbols.

Claim 63

The method according to claim 53 wherein said step of selecting includes the step of selecting said samples from two different wrays, a first wray including I samples from one of said rays and a second wray including Q samples from one of said rays.

Claim 64

The method according to claim 53 wherein the step of correlating includes computing a fast Walsh transform to correlate the samples to known Walsh-Hadamard sequences.

Claim 65

The method according to claim 53 wherein said set of known code sequences are code words in an orthogonal block code.

Claim 66

The method according to claim 53 wherein said set of known code sequences are code words in a bi-orthogonal block code.

Claim 67

In a spread spectrum communications system, a method for receiving spread spectrum information signals and determining received data sequences, said method comprising: receiving a composite signal of overlapping, transmitted signals; sampling said composite signal; selecting at least two wrays of composite signal samples; and combining said composite signal samples in each of said selected wrays to recover the transmitted data signal.

Claim 68

In a spread spectrum communications system, a method for receiving spread spectrum information signals and determining received data sequences, said method comprising: receiving a composite signal of overlapping, transmitted signals; sampling said composite signal; selecting at least two wrays of composite signal samples; and combining said composite signal samples in each of said selected wrays to recover the transmitted data signal.