Architecture And Radio Resource Management Of Multiple BS Cooperative Communication System

This thesis focuses on the architecture and radio resource management of multiple base stations cooperative communication systems.The target is to propose low-complexity,high-performance, broadly applicable radio resource algorithms for multiple base stations cooperative systems.This research mainly includes the novel architecture called orderly distributed communication system,the power control algorithms for multiple base stations, and the multiuser scheduling policy for multicell circumstance.First,in consideration of the drawbacks of the traditional cellular system and the properties of radio propagation,this thesis proposes a novel wireless network architecture called orderly distributed communication system,which is compatible with the extant system. The new architecture introduces the distributed process into a strictly orderly system.It fully utilizes the resource of each base station by dividing the coverage area into uni-covered regions and cross-covered regions.This thesis studies on the regular triangular cell and regular hexangular cell.For each architecture,the system capacity is analyzed,and the rules of choosing the system parameters are given.Comparing the ergodic and outage throughput of the novel architecture with those of traditional cellular systems and fully distributed systems,it can be found that the new architecture can effectively suppress the interference and improve the capacity by introducing both macro diversity and frequency reuse between multiple base stations.Power control is an effective approach to suppress the interference in cellular network. This thesis proposes a power control method which is based on the Stackelberg game for the traditional cellular systems or uni-covered regions.It improves the system capacity by modeling the power control problem as a leader-follower game,and establishing a global price to eliminate the users with bad channel condition.This thesis proves that this game converges to a unique equilibrium in a large-scale interference ideal network,and proposes a price update function to adjust the price of the whole network.Numerical results show that this algorithm performs well especially in a large-scale system.This thesis also studies the power control method for cross-covered regions and macro diversity mode.First,for one cell or cross-covered region case,when the orthogonal spacetime coding is used to obtain the macro diversity gain,this thesis proposes a power allocation scheme among different base stations.To minimize the upper bound of the ergodic pair-wise symbol error rate is equivalent to perform water-filling against the large-scale fading.To reduce the complexity,a novel power allocation method is proposed by approximating the original problem.This method assigns a weight to each base station,and allocates power proportional to these weights.In most situations,the weight-based method can achieve almost the same performance as water-filling.Second,for the multiple cells or cross-covered regions case,this thesis proposes a novel primary-subsidiary cooperative power control method.This algorithm divides the service base stations as primary base stations and subsidiary base stations.The subsidiary base station adjusts its transmit power according to the transmit power of the primary base station.The new algorithm can be implemented in a distributed way,and significantly improve the system capacity while compared with the extant power control method for fully distributed systems.Moreover,a novel primary-subsidiary cooperative communication policy for a flat network is proposed.Based on the study of power control,this thesis further proposes an interference matched multiuser scheduling policy in multicell circumstance.The target is to maximize the system throughput under signal to interference balanced power control method.This policy takes the channel conditions and potential interference of each user into consideration,and schedules matched users in each slot.This thesis proves that the interference matched algorithm optimizes the lower bound of the system capacity irrespective of the cell number and the user number.Moreover,the new algorithm has an extremely low complexity,and can be implemented in a fully distributed way.Simulation results show there is only a very narrow performance gap betweenthe new method and the optimal scheduling.And over the extant round robin scheduling and power matched scheduling,the novel method achieves a great performance gain,especially in a large-scale system.