Performance Analysis Of Multi-Cell Systems With Unequal Power Cochannel Interferences

Signal transmission in wireless communication systems are usually subject to additive white Gaussian noise, multipath fading and co-channel interference (CCI). It is well known that multi-users within the same cellular and adjacent cellular users with the same frequency use the same frequency to send and receive signals in the practical cellular mobile communication system. Therefore, it brings in the mutual interference between multiple users inevitably. To some extent, this will affect the quality of signal reception and reduce system performance. How to reduce co-channel interference on the performance of cellular systems has been a hot issue for industry research. At present, some technology of resisting interference and fading in the cellular system have been used, such as maximum ratio combining technology and multi-user diversity technology. Therefore, the reasonable use of multi-user diversity gain can effectively improve system performance. In this paper, we put the performance of the system with co-channel interference as a honey research topic. We study co-channel interferences with the unequal power on the influence of the performance of the multi-cellular system as well as the role of multi-user diversity technology to improve system performance.First, this paper studies the multi-cellular cell system model, discuss in detail the influence of the unequal power co-channel interferences on multi-cellular systems outage probability and average bit error rate performance when co-channel interferences obey the Rayleigh distribution and the Nakagami-m distribution and prove that the co-channel interferences have a significant impact on multi-cellular system performance.Second, we further raise the maximum ratio combining (MRC) strategy on the basis of the previous work and then discuss the performance of the system with MRC when co-channel interferences obey the different distribution. which illustrate that maximum ratio combining technology (MRC) can increase the antenna diversity gain effectively and overcome the interference by Monte-Carlo simulation experiment.The last, at the basis of using the maximum ratio combining, a multi-user diversity technology is further proposed to improve system performance by combining maximal ratio combining and multi-user diversity technology. By establishing a model of multi-input multi-output system using the maximal ratio combining technique, we discuss and compare outage probability and average symbol error rate performance of multi-user diversity and no multi-user diversity system under perfect channel state information. Secondly, the average capacity of maximum ratio combining and multi-user diversity cellular systems is discussed under imperfect channel state information and multi-cellular environment. Consider the existence of co-channel interference and channel estimation error, we analyze and compare the impact of the multiuser diversity, unequal power and channel estimation error on the average capacity of cellular system with the multi-user diversity and the maximum ratio combining and further prove that when many users share the same channel at one time, the total throughput of the communication system can be maximized by allocating the common radio resource to the user having the best channel quality at a given time and the multiuser diversity gain can be obtained, which explain the multi-user diversity can enhance the performance of cellular systems while co-channel interference and channel estimation error co-channel interference and channel estimation error is not conducive to system performance.Finally, this article summarizes the full text and plans the next step in the research work. In order to verify the correctness of the mainly theoretical analysis, each part all design the appropriate Monte-Carlo simulation experiment in this paper.