The Application And Research Of Polar Codes In Wireless Metropolitan Area Network

Polar codes,proposed by E.Arikan in 2009,have been proven theoretically to achieve the symmetric capacity of any given binary-input discrete memoryless channel.Due to the structural property and the superior capacity-achieving performance,polar codes have essential research value and have been widely concerned.Presently,the polar codes scheme has been selected to the control coding scheme of the 5G e MBB scene.Polar codes have a good prospect of application.The wireless metropolitan area network(WMAN)belongs to the broadband wireless access(BWA)technology.IEEE 802.16 standard has been made for WMAN by the international association of electrical and electronics engineers(IEEE).This standard can not only solve the problems in two aspects of the physical environment and the Qo S,but also can satisfy the BWA and the "last mile" access to the market needs.Studying the application of polar codes in WMAN has a certain practical significance and engineering application value.This paper mainly studies the polar codes in the application of wireless metropolitan area network,and completes the following several aspects:1.Determine the channel model of wireless metropolitan area network,and make analysis on the channel environment.The channel model in 802.16 system can be divided into line-of-sight propagation model and non-line-of-sight propagation model.The former is mainly affected by the rain fading,while the latter is by the multipath delay spread and the doppler frequency shift.We will focus on the non-line-of-sight propagation,and adopt the revised Stanford University Interim(SUI)channel model.2.On the basis of the SUI channel model,we introduce and analyze the WMAN-OFDM system to resist the multipath effect.Something has been definitely introduced in the 802.16 standard,such as the system parameters and FFT of 256 points.The sampling factor varies with the channel bandwidth,and there are four choices of the ratio of the cyclic prefix time to the useful time.3.For the SUI channel model,we put forward a specific construction method of polar codes,the Monte Carlo.With the construction method,we make simulation on the SUI channel by the SCL-CRC16 and SC decoding algorithm.There are 6 kinds of typical channel in the SUI channel model,corresponding to three types of terrain.This paper selects the SUI-1,SUI-3 and SUI-5,respectively corresponding to the flat,centered,and mountainous terrain.4.We compare polar codes with LDPC in the process of simulation analysis.The analysis shows that polar codes have good performance on the SUI channel,especially by using the SCL-CRC16(L = 16)decoding algorithm,which makes polar codes comparable to LDPC in terms of performance.The two simulation curves have an intersection at high signal-to-noise ratio(SNR),and there is always a critical SNR.When SNR is less than the critical value,polar codes have performance advantage over LDPC.When SNR is higher than the critical value,the performance of LDPC is better.