Application of Antenna Diversity in HIDMA Scheme Using Gold Codes

In Interleave Division Multiple Access (IDMA) scheme, interleavers play a vital role. In recent years IDMA have been proved to give the good performance in terms of data security and noise immunity, but huge memory requirement and complexity are major issues for specifying the interleaver pattern in this scheme. This paper presents the helically interleaved IDMA (HIDMA) system. HIDMA system not only achieves the performance as well as RI-IDMA (randomly interleaved) but also renders the system with low complexity and significant reduction in memory requirement. The performance can be improved significantly by the inclusion of Gold Codes in the system. Further, to take the system into practical considerations the performance of the system is examined in a fading environment. Maximal Ratio Combining (MRC) approach has been utilized using antenna diversity (transmit diversity) to combat the fading error. Evaluation is done on the basis of mathematical analysis and simulations in Rayleigh Fading Environment.