Patent ID: 6873664
Filing Date: 2005-03-29
Classification: H04B,H04J

Abstract:
1. A method of detecting from a received signal a long code composed from first and second codes interleaved with each other, wherein the first code has a length of n symbols and the second code has a length of m symbols, the method comprising: a) demultiplexing the received signal into alternating symbol streams; b) correlating the first symbol stream with a first reference code to produce a sequence of first correlation signals, and correlating the second symbol stream with a second reference code to produce a sequence of second correlation signals; c) summing the sequence of first correlation signals over a first predetermined length to produce a first correlation sum, and summing the sequence of second correlation signals over a second predetermined length to produce a second correlation sum; and d) processing the first and second correlation sums to produce a signal indicative of the phase of the long code, wherein c) includes c2) adding a current second correlation signal x c3) subtracting first and second sum delay values from the first and second sums, respectively, to generate first and second difference signals, wherein the first sum delay value corresponds to the (x c4) storing the first sum in a first sum delay memory at a current address of the first sum delay memory, and then incrementing the first sum delay memory=s address modulo n·m; and c5) storing the second sum in a second sum delay memory at a current address of the second sum delay memory, and then incrementing the second sum delay memory=s address modulo n·m.