A Novel Diversity Technique to Improve the Channel Coding Performance in Wireless Communications

This thesis focuses on utilising the available resources in the wireless communication system to improve the performance of a high data rate FEC concatenated code without additional bandwidth or extra power. Over recent years, high data rates and reliable communication are essential demands in wireless communication. At the same time, wireless communication is supposed to have good coverage and quality, exploit the limited resources (i.e. power and bandwidth) as efficiently as possible, and can be operative in diverse types of environments such as urban, suburban, and rural. Wireless communication channels experience impairment which causes overall system performance degradation. One of the major performance degradation factors is the multipath propagation phenomenon which leads to fading problem and unreliable system. The multipath propagation phenomenon results in, copies of the transmitted signal are travelled over different paths. The replicas can undergo various time delays and attenuation. One of the methods to improve the wireless communication performance is Forward Error Correction (FEC) codes. The investment of FEC requires either the channel bandwidth to be increased or the transmission rate to be decreased. Thus, it is necessary to keep a high rate of transmission, but not at the cost of extra bandwidth or additional power. Therefore, the thesis proposes a novel diversity technique which is known as Multipath Forward Error Correction (MPFEC), and the diversity processing method is known as Column Weight Multipath Combiner (CWMC). Furthermore, the thesis suggests RS(255,239)+BCH(1024,963) concatenated code as a high rate code for wireless communication systems. The MPFEC technique considers some of the multipath signals, which result from the multipath phenomenon, as an existing resource (redundant copies of the transmitted signal). These replicas are utilised to enhance the performance of the proposed high data rate FEC code without increasing the channel bandwidth or power. Based on the simulation results and analysis presented in the thesis, it was found that the proposed diversity technique improved not only the performance of the proposed concatenated code but also enhanced the performance of other low redundancy FEC codes. Moreover, the uncoded wireless communication performance with the MPFEC technique has shown improvement in the bit error rate. The performance of the different wireless communication systems was compared with system performance before and after applying the MPFEC technique with and without the proposed concatenated FEC code.