User Selection And Power Control Scheme In Comp System And The Lte Link Level Simulation Platform Construction

With the development of wireless communication market demands and the corresponding technology, Long Term Evolution (LTE) comes much closer to the industry area from research area. Orthogonal Frequency Division Multiplexing (OFDM) and Multi-Input Multi-Output (MIMO) technologies are widely applied in LTE, which enhances the total system throughput and improves the intra-cell inference. However, since OFDM network employs the same frequency, inter-cell interference becomes a prominent issue. LTE-Advanced is the evolution version of LTE, the coordinate multiple point (CoMP) technology proposed in LTE-A can solve inter-cell interference, and develop the performance of cell-edge users. CoMP jointly coordinates between multiple cells, serving users in cell-edge to decrease interference. Therefore, how to make full use of CoMP to enhance cell-edge users’ performance and throughput of the whole system is an urgent issue to be solved.In order to improve the performance of cell-edge users, this paper researches on user selection algorithm and power control algorithm of CoMP system. Besides, we investigate the LTE technology to build link level simulation platform. The key work in this paper is as follows:First, the existed user pairing algorithm and its application are concluded here. Furthermore, we overview the classic power control algorithm, and illustrate the importance of power control.Second, multi-user selection and power control (MuS-PC) is proposed as an efficient scheme in uplink Coordinated Multiple-Point Multiple-User Multiple Input Multiple Output (CoMP-MU-MIMO) transmission/reception. In this paper, we jointly consider user’s signal to interference plus noise ratio (SINR) and proportional fairness (PF) to maximize the total channel capacity in multi-user selection by formulating a penalty function. To simplify the penalty function’s computation, particle swarm optimization (PSO) algorithm is introduced. In addition, power control is adopted to maximize overall energy efficiency. Simulation results demonstrate that the MuS-PC scheme can not only obtain the optimal total channel capacity while guarantee each user’s quality of service (QoS) and PF, but also largely reduce computational complexity and improve energy efficiency. As a result, the poor communication quality of CEUs can be enhanced.At last, based on the communication procedure of LTE, we build the link level simulation platform by MATLAB. The simulation platform adopts OFDM, carries out QAM modulation and demodulation by subchannel granularity. Besides, to confront white noise, we use convolutional encoding and viterbi decoding to improve system performance. Furthermore, channel frequency-domain equalization employs pilot signal to verify signal after going through the time-varying channel, and computes bit-error rate in the reception part. Simulation platform can measure channel states by bit-error rate, and check the performance of frequency equalization for practical use.