A Sample Timing Offsets Compensation Algorithm And Performance Analysis For Coordinated Multipoint To Multiuser System

With the evolution of IMT-Advanced technologies, a series of new technologies emerged in the next-generation broadband wireless mobile communications. Coordinated multipoint technology is a forward-looking technology concept, designed to improve cell-edge users’ communication quality. Among Co MP multiuser communication system, through cooperation between the base stations can reduce the impact of interference on the system performance to bring benefits. Coordinated Multi-Point technology brings to the system gain in case the system is fully synchronized. However, in practical systems, because of the user’s mobility,Coordinate multipoint to multiuser symbol timing synchronization exist the deviation, bringing the inter-symbol interference and the system quality of service attenuation. In this paper, the symbol timing deviations compensation algorithm of coordinated multipoint multiuser communication systems was studied, and made a detailed analysis of its performance,.The main research results obtained are as follows:1. A symbol timing deviations compensation algorithm of coordinated multipoint multiuser communication systems was studied. Proposed a pre-compensation base station, the user after joint compensation algorithm. In the case of proving coordinated multi-point multi-user bias can not be completely eliminated, the amount proposed partial constraint within a tolerable range when the partial remainder, the establishment of constrained optimization equation, solving the pre-compensation value and the compensation value after completion enhanced symbol timing offset compensation algorithm design.2. According to the established equation constrained optimization study the least squares method for solving the two pre-compensation value. One is the use of the generalized inverse matrix,the other one is a matrix QR decomposition with constraints loop iteration method for solving. Focus on the QR decomposition method of least squares, made improvements to its basic solution method, introducing constraints, using an iterative approach to solving cycle, eventually solved after pre-compensation values and pro-compensation values.3. Use the computer to LTE-A downlink simulation example,the performance of the enhanced compensation algorithm is validated.Two solution algorithm based on optimization equations were simulated respectively. And two optimization algorithm were compared with consumption of time and compensation performance.4. Coordinated multi-point to multi-user signal overhead impact on system performance is analyzed. Timing offsets compensation algorithm overhead information and the amount of time remaining for the partial impact on the system user throughput were studied with computer simulation. The results show that the number of base stations to coordinate should be chosen and to compensate timing offsets is essential.