Method and apparatus for successive cancellation using multiple signal timing

Abstract

A direct sequence CDMA receiver receives a sampled signal. A subsampling unit sub-samples the sampled signal in accordance with timing information to produce a chip-sampled signal. An equivalent code generator generates equivalent codes using the timing information and information about user spreading codes. A processor processes the equivalent codes to produce an orthogonalized code and a correlator correlates the chip sampled signal with the orthogonalized code to produce a despread value.

Description

field of invention [0001] This invention relates to direct sequence CDMA receivers, and more particularly to utilizing one sample per chip for demodulation to reduce receiver complexity. Background of the invention [0002] Wireless communications are advancing at an extraordinary pace as more radio spectrum becomes available for commercial use and cellular telephones become commonplace. Currently, technology is developing from analog communication to digital communication. Speech can be represented by a series of bits. These bits are modulated and sent between the base station and the mobile station. Each base station and mobile station has a transmitter and a receiver. The receiver demodulates the received waveform to recover the bits, which are then converted back to speech. Demand for data services such as electronic mail and Internet access that require digital communication is increasing. [0003] A variety of digital communication systems are currently available....

AI Technical Summary

Problems solved by technology

However, quadrature with multiple samples per chip greatly increases the complexity

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