Adaptive modulation system with punctured convolutional code for high quality personal communication systems

This paper proposes an adaptive modulation system with a punctured convolutional code for land mobile communications to achieve high quality, high bit rate, and high spectral efficient data transmission in multipath fading environments. The proposed system adaptively controls the coding rate of the punctured convolutional code, symbol rate, and modulation level according to the instantaneous fading channel conditions. The performance in fading environments is 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