Patent ID: 7738606

Claim:
A correlation subsystem for a receiver that receives spread-spectrum signals, including: an array of complex accumulation registers that over multiple code chips accumulate correlation measurements that correspond to samples of the received signal at sample times that are asynchronous to code rate, the complex accumulators being associated with code chip ranges that span all or a portion of one or more code chips; a code phase decoder that controls the complex accumulation registers to direct respective correlation measurements to the complex accumulation registers that are associated with the code chip ranges from which the samples are taken, the code phase decoder decoding values that correspond to estimated code phase times of the samples; and a processor for selectively combining the accumulated values from two or more accumulation registers to produce correlation values for use in one or more correlation techniques, multipath mitigation techniques, or both, with a given code range that is associated with a code tracking point and a number of ranges both before and after the given range being selected for combining to determine a punctual correlation value and a code error is determined as: C error = I P ⁢ I E - L + Q P ⁢ Q E - L I P 2 + Q P 2 × chipsize where I P and Q P are the in-phase and quadrature-phase components of the complex punctual accumulation value P P and I E-L and Q E-L are the in-phase and quadrature-phase components of the complex early-minus-late discriminator P E-L .