fixed rate coding in terms of SNR and average throughput was obtained. In fact, the concept of variable rate adaptive In this paper, we propose a bandwidth efficient error cor- coding and modulation has been widely applied in 3rd genrection scheme, namely the variable rate adaptive bit- eration TDMA systems like Enhanced Data rate for GSM interleavedtrellis coded modulation (ABICM), for wireless Evolution (EDGE) and UWC136. mobile channel. The code rate and modulation level are It is therefore a natural extension to combine the above varied accordingto the current channel state to exploit the two concepts, namely the BICM and the variable rate adap timevarying nature of the wireless channel. Design chal- tive channelcoding,together to achievea synergy. One very lenges to achieve symbol-by-symbol adaptation, component simpleway to combinethe two conceptsis to adopt a multicodes design, puncturing and interleaving design, adapta- frame adaptation technology similar to the EDGE system tio...
Vincent K. N. Lau