基于Gram-Schmidt正交化法的串行干扰消除算法

基于Gram-Schmidt正交化法,提出了一种改进的串行干扰消除算法.不同于传统的串行干扰消除算法,该算法运用Gram-Schmidt正交化法,通过扩频序列获取正交序列作为最优解扩码,使得检测器每一级最强用户的解扩码与其他用户的扩频码所张的子空间正交,从而实现对多址干扰的完全抑制.给出了具有幅度失配的系统误码率近似公式,讨论了幅度失配对检测性能的影响.仿真结果表明,改进算法能有效抑制CDMA系统中的多址干扰,改善系统性能.     

一种联合式自适应多用户检测算法

自适应多用户检测器没有充分利用多用户信号特点，为此，提出联合式自适应算法，以接收信号作为参考信号，而自适应滤波器的输入信号变为各用户扩频序列的采样值，分析和仿真结果表明。该类自适应多用户检测器具有更高的收敛速度和抗远近效应的能力。     

A Soft Parallel Interference Cancellation Algorithm in WCDMA

A two-stage soft parallel interference cancellation (SPIC) algorithm in WCDMA system is proposed. The performance of the algorithm is analysed in perfect power control and near-far case, and the influence of the timing error on the system BER is discussed. Analysis and simulation show that the SPIC technique can enhance system capacity, and have a good ability to resist near-far impact. With its simple structure, it has good potential for practical applications.     

Improved Space-Time Selective Interference Cancellation Scheme for CDMA Systems

IntroductionAdaptiveantennaarrayscanreduceco channelinterference (CCI)fromotherusersaswellasmitigatetheeffectofmultipathfadinginwirelessenvironments .SinceCDMAsystemsareinterferencelimitedinnature ,smartantennahasbeenregardedasoneofthecoresystemcomponents…     

智能天线系统中干扰抵消的算法研究

首先分析了智能天线在CDMA系统中应用,理论分析了通过空间特征向量来对其实现“零陷“,提出采用压低基站的上行干扰提升系统的性能的新算法,实验仿真显示:该算法通过空域滤波,能够显著提高系统性能.     

基于分组纠错码指导的多分辨率SIC算法

采用维纳均衡器和能量均匀分布扩频矩阵的SOFDM系统在频率选择性衰落信道中的误比特率小于OFDM系统,但是维纳均衡器的使用引入了子信道间干扰,且SOFDM系统的各子信道信干比相等,现有的相继干扰消除(SIC)算法无法有效地消除该干扰.为解决这一问题,文中提出了基于分组纠错码指导的多分辨率SIC算法,描述了该算法的子信道间干扰消除原理和实现过程,并通过计算机仿真验证了该算法的有效性.     

CDMA系统性能的精确分析

针对高斯假设的方法对多用户系统进行分析具有一定的局限性,对CDMA系统相关接收的性能进行精确分析,得到系统的误码率曲线。实际仿真结果表明,该分析方法比基于高斯假设的分析更精确。     

BLIND DIFFERENTIAL ADAPTIVE MULTIUSER DETECTION

IntroductionThe problem of combating multi- access interfer-ence ( MAI) in CDMA systems has receivedgreat attention recently[1～ 3] . In Ref. [4 ] ,M.Honig employed a blind adaptive multiuser de-tector based on the minimization of mean- out-put- energy( MOE) to overcome MAI,and itre-quired no more knowledge than did the conven-tional single- user receiver.Surplus energy wasemployed to suppress the effects of multi- accessinterference and thus provided an optimal detec-tion solution. The…     

A New Parallel Algorithm in Power Flow Calculation: Dynamic Asynchronous Parallel Algorithm

Based on the general methods in power flow calculation of power system and onconceptions and classifications of parallel algorithm, a new approach named DynamicAsynchronous Parallel Algorithm that applies to the online analysis and real-time dispatching and controlling of large-scale power network was put forward in this paper. Its performances of high speed and dynamic following have been verified on IEEE-14 bus system.     

A Dynamic Job Scheduling Algorithm for Parallel System

One of the fundamental problems in parallel and distributed systems is deciding how to allocate jobs to processors. The goals of job scheduling in a parallel environment are to minimize the parallel execution time of a job and try to balance the user‘s desire with the system‘s desire. The users always want their jobs be completed as quickly as possible, while the system wants to service as many jobs as possible. In this paper, a dynamic job-scheduling algorithm was introduced. This algorithm tries to utilize the information of a practical system to allo-cate the jobs more evenly. The communication time between the processor and scheduler is overlapped with the computation time of the processor. So the communication overhead can he little. The principle of scheduling the job is based on the desirability of each processor. The scheduler would not allocate a new job to a processor that is already fully utilized. The execution efficiency of the system will he increased. This algorithm also can he reused in other complex algorithms.