VLSI implementation of soft output Viterbi equalizers for mobile radio applications

Advantageous optimum and suboptimum receiver structures operating in the IF domain, therefore enabling real signal processing and reducing hardware expense, are presented. Petri net representations of the soft output Viterbi equalizer (SOVE) and the transition metric calculation combined with so-called add-soft-output-select recursion are given. Hence, an efficient design flow and an easy-to-accomplish validation of the functionality of the design is achieved. Further, the impact of the quantization and the duration of the channel impulse response on both the performance and the complexity of SOVE VLSIs are considered