| 摘要 |
A maximum likelihood (ML) detector provides improved performance in the presence of multiple user interference (MUI), particularly performance of a multiuser receiver for asynchronous CDMA. The detector can be implemented using a Viterbi algorithm, this greatly reducing system sensitivity to MUI. An approximation to the ML detector provides a sparse trellis search based on the structure of the ML detector. The resulting detector, which may be referred to as a reduced-complexity recursive detector (RCRD), has a dynamic structure that allows a trade-off between complexity and performance. Use is made of a unique metric to define the trellis-structure and the M-algorithm to reduce the number of surviving paths. The metric calculation is then repeated at decision points to provide soft-decision information for further signal processing, soft-decision decoding of an error-correction code, or iterative reception of the multiuser signal.
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