Design & implementation of efficient turbo equalizer for noise reduction

Abstract

This paper presents design and implementation of efficient turbo equalizer for Noise reduction. Linear turbo equalizer is a combination of soft input soft output (SISO) equalizer and soft input soft output (SISO) decoder, which exchanges their information iteratively. The propose architecture uses least mean square (LMS) adaptive algorithm for equalization of received symbols in the design of SISO equalizer block as hardware intricacy required to design equalizer is small when compared to other equalizers. SISO (soft input soft output) decoder block has been designed using sliding window log-MAP algorithm. The Log-MAP decoding algorithm is selected for implementation of the constituent Soft-Input/Soft-Output (SISO) decoder; the algorithm is approximated by a fixed-point representation that achieves the best performance/complexity trade-off. Our simulation results shows that the proposed design and implementation gives better bit error rate (BER) performance and convergence rate over conventional equalizer for prokis channels.