Patent ID: 7668228

Claim:
In a receiver for ranging signals which comprise RF carriers, each of which is bi-phase modulated with a different pseudo-random code, the receiver having a controllable code generator for generating a local replica of a selected transmitted code, and further having a delay lock loop that generates an error signal used to control the code generator to align the local code replica with the direct-path component of the received signal, the improvement comprising: A. means for dividing at least the rising edge of each receiver code chip into multiple intervals and providing enabling signals corresponding with the intervals; B. a set of accumulators, each of which is enabled to receive a sample of the signal in response to a different one of the enabling signals, whereby the contents of the set of registers provide an outline of at least the beginning of the rising edge of a received code chip; C. an MMT processor that 1) compares the outline of the start of the rising edge with a model of the outline of the rising edge of the received signal, and 2) provides corrections to the delay tracking loop to make the timing of the code generator more closely correspond to the zero crossing of the direct path component of the received signal and thereby mitigates the effect of multi-path components in the received signal.