The Performance Analysis Of Space-Time Trellis Codes In Non-Gaussian Noise

With development of the third generation mobile communication technology,the broadband multimedia services come forth constinuously and the mobile transmission data rate becomes higher and higher.The frequency resources become more limited. The key of modern wireless communication technology developing is making full use of the limited communication resources efficiently.The multiple-input multiple-output (MIMO) technology can be used to improve the capacity,signals error probability and frequency efficiency significantly without extra frequency bandwidths and transmitted power.Being the key technology of MIMO,space-time coding(STC) can obtain the information rate which approaches the information theoretic capacity by introducing spatial and temporal correlation at transmission.Also it indicates a new idea of solving the transmission rate in wireless communication systems.Space-time trellis code(STTC) is regarded as the optimum code,which satisfies the design criteria of space-time coding by configuring the trellis structure and achieves the compromise of encoding complexity, performance and frequency efficiency.However,the communication system can not avoid the multipath fading and noise interferes.Fortunately,orthogonal frequency division multiplexing(OFDM) is a multicarrier transmission scheme that can be against multipath fading.Yet there are many phenomena in communications that contribute in producing noise that has a non-Gaussian distribution,that is to say,non-Gaussian noise is prevalent in wireless environments and often impulsive or long tail in many applications.The non-Gaussian noise is a new focus which is deserved to pay more attention except typical Gaussian in the wireless communications.The major point of this thesis is to research the performance of space-time trellis code in non-Gaussian noise environment.Firstly,we describe the surrounding of the wireless communication channels.Then basing on the study of non-Gaussian noise environment,the typical non-Gaussian noise models of K distribution,SαS distribution, Class A distribution and mixture Gaussian distribution noise are established.The methods of spherically invariant random process and histogram are respectively used to generate the non-Gaussian random variables corresponding.Secondly,we derivate the pairwise error probability(PEP) of space-time trellis code over fast and slow fading channels.And the signals error rate(SER),frames error rate(FER) performance of space-time trellis code is investigated and analyzed by Monte Carlo simulation over correlated and noncorrelated fading channels in the non-Gaussian noise which is proposed above.In addition,in order to complete tramsmiting of information high-efficiency,combining the OFDM technology,the performace of STTC-OFDM is studied over frequency-selective fading channels which is called COST 207 and giving the results of simulation which are worse than the Gaussian noise over the two environments of RA and TU which belong to the models COST 207.