Pragmatic approach to adaptive turbo coded modulation

This paper presents a pragmatic adaptive scheme for TuCM over slowly fading channels. The adaptive scheme employs a single turbo coded modulator composed of a variable-rate turbo encoder and a variable-rate variable-power MQAM for all fading regions, so it has an acceptable complexity to implement. The optimal adaptive TuCM scheme is determined subject to various system constraints. Simulations have been performed to measure the performance of the scheme for different parameters. It is shown that adopting both the turbo coded modulator and the transmit power achieves a performance within 2.5 dB of the fading channel capacity.