CAREER: Multi-user Receivers for Advanced Wireless Systems

这项研究的广泛目标是利用两者的性质 未来的通信业务和通信 高性能接收机的建设中的通道， 多用户码分多址（CDMA）信号。 问题包括带宽效率、接收器/发射器 复杂性和服务质量（QoS）。 两个主要研究 将研究CDMA接收机设计中的以下领域： 速率通信和信道均衡。为了 适应各种可能不同的源（语音， 数据和视频信号），多速率通信方案必须 发展。可能的来源，如语音、视频和数据 通信具有固有的不同QoS要求。QoS参数包括：比特率、允许延迟、性能和 源优先级。当前的恒定比特率范例 无线网络将不提供这种多速率服务 未来本研究的重点是：（a）开发最佳的 用于各种多速率接入方法的检测器， 比较，（B）创建绩效度量， QoS需求将被构建，以及（c）构建多用户接收器， 明确地利用窄带和 宽带用户信号。一个主要的考虑因素是失真 由无线电信道的传播效应引起。接收器 以对抗多径和衰落的影响。虽然在无线系统的上下文中的均衡是一种可实现的技术， 充分探索的问题，这项研究的新奇在于， 考虑（a）必要的参数估计方法， 适应新用户，（B）专业化 现有的用于CDMA信号的盲均衡技术 （c）以适度的复杂性实现， 半盲方法，以充分利用现有的任何信息 关于CDMA信号和通信信道。

The broad goal of this research is to exploit the nature of both the future communications traffic and the communications channel in the construction of high performance receivers for multi-user Code-Division Multiple-Access (CDMA) signals. Issues include bandwidth efficiency, receiver/transmitter complexity, and quality of service (QoS). Two main research areas within CDMA receiver design will be investigated: multi rate communications and channel equalization. In order to accommodate a variety of potentially disparate sources (voice, data and video signals), multi-rate communication schemes must be developed. Possible sources such as voice, video, and data communications have inherently different QoS requirements. QoS parameters include: bit-rate, allowable delay, performance, and source priority. The constant bit-rate paradigm of the current wireless network will not serve such multi-rate services of the future. The focus of this research is to: (a) develop optimal detectors for the various multi-rate access methods and compared, (b) create performance measures which capture QoS needs will be constructed and (c) construct multi-user receivers to explicitly exploit the redundancy in the mixture of narrowband and wideband user signals. A major consideration is the distortion induced by the propagation effects of the radio channel. Receivers to combat the effects of multipath and fading will be developed and analyzed. While equalization in the context of wireless systems is a well-explored problem, the novelty of this research lies in the consideration of (a) parameter estimation methods necessary for the accommodation of new users, (b) the specialization of existing blind equalization techniques for CDMA signals which are achieved with moderate complexity, and (c) the development of partially blind methods to fully exploit any information present about the CDMA signals and the communication channel.