Automatic gain control of 16 QAM in microcell Rayleigh fading channel

In this paper, we introduce the time constant of an AGC (automatic gain control) loop filter which is very important in the micro cell environment and its duration should be around 12 /spl lambda/ of the carrier frequency. Furthermore, we introduce the performance measurement system of pilot symbol assisted 16 quadrature amplitude modulation (QAM) system which use 3/4 trellis coded modulation with a sub-optimum Viterbi decoder. The sub-optimum Viterbi decoder required only 1/3 computation complexity of the conventional Viterbi decoder, with negligible performance degradation in the field test.