Experimental study of multi-user detector with trellis-coding for microcellular radio

This paper reports the experimental study of multiuser detectors in TDMA for higher spectral efficiency. In particular, a trellis-coded cochannel interference canceller (TCC) and interference canceling equalizer (ICE) have been studied. TCC and ICE employ maximum likelihood sequence estimation extended to multi-signal detection. These techniques show excellent performance for cancelling and equalizing signals especially in frequency selective fading environments. However, performance of ICE is severely degraded due to the lack of the Euclidean distance in line-of-sight (LOS) propagations. TCC uses the trellis-coded modulation for improving this degradation of ICE. Consequently, the TCC scheme is expected to be superior to ICE in microcellular radio communications, where the propagation channel is often LOS. By laboratory experiments, this paper confirms that TCC is significantly superior to ICE especially in LOS propagation channels. In the experiments, the bit-error-rate performance of TCC and ICE is given by a prototype of RF transmission system consisting of two transmitters and two receivers.