Adaptive modulation system with variable coding rate concatenated code for high quality multi-media communication systems

This paper proposes an adaptive modulation system with a concatenated code (AMS-CC) for land mobile communications to achieve high quality, high bit rate transmission in Rayleigh fading environments. The proposed system adaptively controls the coding rate of the inner convolutional code, symbol rate, and modulation level according to the instantaneous fading channel conditions. The performances in Rayleigh fading environments are evaluated theoretically and by computer simulation. The results show that the proposed system can realize higher quality transmission without the degradation in average bit rate compared to conventional adaptive modulation systems.