The Research Of Multi-Carrier System Based On Complete Complementary Codes

The multi-carriers CDMA (MC-CDMA) is a kind of the combination of OFDM and CDMA technology,thus advantages of both techniques are exploited,has the good ability of anti-intersymbol interference (ISI)which cause multipath effect,at the same time, it has CDMA capacity characteristics etc,and its modulation and demodulation are realized by using the discrete Fourier transform(DFT),can reduce the system complexity.In this paper,based on the introduction of the MC-CDMA and complete complementary code,the performance of MC-CDMA system is studied deeply.First of all,researched reduce of peak-average power ratio (PAPR) of MC-CDMA.Proposed the use aperiodic complete complementary code as the MC-CDMA system of spreading codes,and did the simulation confirmation.The simulated results show that the aperiodic complete complementary codes have excellent reduction PAPR function.The peak-average power ratio upper bounded by 3 dB.Next ,designed a kind of MC-CDMA system model based on polyphase complete complementary code.The performance simulations for the model in an AWGN channel and Rayleigh fading channel were studied, and comparisons among Walsh sequence based MC-CDMA system were made.The simulation results show that the MC-CDMA system based on polyphase complete complementary code has excellent BER performance whether in AWGN channel or Rayleigh fading channel.In the end,analyzed the performance of reduce the impact of multiple access interference in the MC-CDMA system based on polyphase complete complementary codes in the theory,and did the simulation confirmation.The simulated results show that this system has the excellent ability of Anti-multiple access interference.