A novel split soft-decision equalizer (SSE) with near-optimum performance is proposed for wireless multipath channels with large delay spread. The concept of SSE is significantly different from the traditional notions of the Viterbi algorithm and decision-feedback equalizer. Instead of dealing with received sequence as a combined sequence, it splits the received sequence into its constituent paths. Using an iterative soft-decision algorithm, reliability of the soft decisions on each decomposed element is improved iteratively. The major advantage of SSE is the independence of computation complexity on channel time dispersion. Joint design of SSE with a soft-decision decoder is also considered in this paper. Performance analysis and simulation results show that performance of the proposed algorithm comes very dose to that of the logarithmic maximum a posteriori decoder.
Bibliographical noteFunding Information:
Paper approved by X. Wang, the Editor for Modulation Detection and Equalization of the IEEE Communications Society. Manuscript received July 15, 2003; revised March 8, 2004 and July 26, 2004. The work of Z.-Q. Luo was supported in part by the National Science Foundation under Grant DMS-0312416. This paper was presented in part at the 10th International Symposium on Personal, Indoor, and Mobile Communications, Osaka, Japan, September 1999.
- Dispersive channel
- Iterative decoding
- Soft decision
- Turbo principle