Performance evaluation of decision feedback equalisation using measured indoor radio channels

In this paper the performance of an indoor wireless communication system is investigated. Adaptive decision feedback equalisers (DFE) are used to mitigate the intersymbol interference (ISI) caused by multipath propagation in the indoor radio channel. The system can be described as follows. It is a 16 quadrature amplitude modulation (16-QAM) system with raised cosine matched filtering with a roll-off factor of 0.50. A realistic channel model is used in the simulations by interpreting complex measured impulse responses of indoor radio channels. The measurements used were done in different types of rooms, and for line-of-sight (LOS) and obstructed (OBS) situations at the frequency of 2.4 GHz. After the signals have gone through the multipath channel additive white Gaussian noise (AWGN) was added. Symbol error rate (SER) performance simulations were done for different signal-to-noise ratios (SNR) and different data rates. On the average the SER performance was a few orders of magnitude (2-4) better than was the case without adaptive equalisation, depending on the SNR