Design of a Novel Multi-Dimensional HCOC Multi-Code Spread Spectrum System Using Pre-Coding Technique for High Speed Data Transmission of DS-CDMA

Recently, Mc (multi-code) modulation/demodulation (modem) technique has been explored for the high speed data transmission in wireless environment. The conventional Mc modem can generate some side effects such as allocating Walsh codes, which motivates the researchers to propose a novel Mc modem method with sub-code. But this proposed system should expand the size of sub-code to provide high-rate data transmission, which also affect adversely the performance of the system with high PAPR (peak to average power ratio). Thus, in this paper, we propose a novel pre-coded multi-dimensional HCOC (high capacity orthogonal code) Mc modem technique to reduce the high PAPR, which enables the performance improvement. This proposed system can be easily designed by concatenating HCOC Mc modem with the generic Mc modem. The pre-coding technique that is used in this paper is called CAC (constant amplitude coding) helps the system maintain the constant transmission power and reduce the maximum transmission power.