Rake receiver with selective ray combining

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.

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.

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.

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.

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.

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.

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.

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.

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.