BER Performance using Almouti-Based SC-FDMA using PN Codes

Abstract

Due to various shortcomings of OFDM, like it is sensitive to Doppler shift, frequency synchronization problems, loss of efficiency caused by cyclic guard interval, it was endorsed to use coding algorithms like STBC which improves efficiency. Another way of increasing the efficiency is using a multiple – access technique like SC-FDMA. SC-FDMA can be described as linearly Pre-Coded OFDMA scheme, as it has an additional DFT Processing Step prefacing the ordinary OFDMA processing. In this paper, Almouti based SC-FDMA is proposed to enhance the system’s BER performance and hence improve efficiency. To use the scheme efficiently, it is trained in time domain by appending the training sequence. Thus PN codes are combined with the Almouti based SC-FDMA, as they have less error probability and noise, to augment system’s BER performance. The performance of the proposed system is compared with STBC-based TFT-OFDM.