Research On Network Coding Base On FSK Modulation

With the rapid development of wireless communication technology, wireless network contacts with people lives and work more closely. This has also put forward higher requirements on the throughput of the network. In recent years, network coding theory is causing for concern, which can take full advantage of the broadcast nature of wireless communications to improve throughput performance. In the conventional communication system, the nodes of the network can only store and forward the received data. After the introduction of network coding, the network node may encode and process the received data, exchanging information in fewer slots, so as to improve system capacity and the robustness of the network. This thesis mainly studies the wireless communication relay technology based on network coding. Given most of the studies on relay communications based on phase shift keying, this thesis focuses on network coding based on frequency shift keying techniques to analyze the effect of frequency offset on the performance of wireless network coding system.In the three-slot wireless network coding scheme, firstly, in the Gaussian channel, when frequency offset is generated in the transmission process, the bit error rate formula of BFSK modulation in non-coherent demodulation is derived, and analyzes impact of the frequency shift on network system. Through simulation, the superiority of BER performance of frequency compensation system is proved. Secondly, non-coherent demodulation error rate of BFSK is derived containing frequency offset in Rayleigh channel, and analyzes impact of the frequency shift on network system in Rayleigh channel. Finally, due to the low bandwidth efficiency of binary frequency shift keying modulation, this thesis studies the M-ary frequency shift keying technology. As the representative, the upper bound of bit error rate of4FSK is derived in the Gaussian channel. When the system generates frequency offset, performance of the three-slot wireless network coding based on4FSK is studied.