Use of radius weighted mean to cluster two-class data - Electronics Letters

Performance in fading dispersive channels: Fig. 2 shows a summarised performance indicator for the non-coherent equaliser receiver. A Rayleigh fading two-path channel is used with varying delay spreads and level of E J N , (energy per transmitted bit over noise power). It can be seen that the useful range of operation is extended to delay spreads of -260x1s. This is a significant improvement over a standard DECT receiver (around five times expansion in the useful range of operation at Eh/N, = 30dB). Simulation results for exponential and Gaussian channels have also shown an acceptable performance over delay spreads of up to 15&200 ns. However the non-coherent structure of the receiver results in some degradation in the performance compared to a coherent equaliser. In fact simulation has shown that a coherent equaliser structure similar to that proposed in [2] (Le Fig. 1 without the differential detector block) can extend the operating range to more than 600 ns. By analysis and simulations we observed that the performance limits of the basic non-coherent equaliser receiver are mostly due to catastrophic constellation distortion caused by the nonlinearity rather than to equaliser breakdown caused by excessive dispersion.