Analysis of Adaptive Pilot Symbol Assisted Modulation with Optimized Pilot Symbol Spacing for Rayleigh Fading Channel

For reliable and high data rate communication, highly spectrally efficient transmission techniques are needed, where channel prediction is an important tool to combat the harmful effects of fading. In this paper, study has been carried out for optimized pilot symbol spacing in PSAM to maximize the spectral efficiency. The PSAM technique is made adaptive by varying the pilot symbol spacing to account the effect of change in CSNR with the help of a low capacity feedback channel. This technique is implemented using Modified Long Range Prediction (MLRP) and Estimation of Signal Parameters using Rotation Invariance Technique (ESPRIT) algorithm. The results of the proposed technique are compared with that of PSAM technique. A considerable improvement in terms of Mean Square Error, Bit Error rate and Average Spectral Efficiency has been achieved.