Space and path diversity combining technique for 10 Mbit/s adaptive modulation/TDMA in wireless communication systems

The variable bit rate function used to support both voice transmission and high bit rate data transmission with its bit rate of more than 1 Mbit/s is widely recognized as one of the important functions for the third generation public land mobile communication systems. This paper proposes an adaptive modulation/time division multiple access (TDMA) using a space and path diversity combining for multimedia wireless communication systems with the bit rate of up to 10 Mbit/s in microcellular environments. To compensate for the maximum delay time of one symbol duration, this paper proposes a new space and path diversity combining technique that resolves and combines the first and delayed paths. In the proposed adaptive modulation system, the modulation level and symbol rate are controlled according to the signal to distortion power ratio after diversity combining to maximize the average bit rate with satisfying a certain BER. Computer simulation confirms that the proposed scheme can achieve 10 Mbit/s transmission in microcellular environments with its delay spread of up to 250 ns