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Áp dụng DSP lập trình trong truyền thông di động P5

The increasing demand for communications services and the desire for increased data throughput in modern communications systems has fueled research and development into the use of adaptive antenna arrays. Since frequency bandwidth is in short supply and is expensive to acquire, the ability to separate users based on their spatial parameters is very attractive for wireless networks. Adaptive antenna arrays offer the ability to increase the Signal-to-Noise Ratio (SNR) of a wireless communication link while at the same time permit the cancellation and removal of co-channel interference. . | The Application of Programmable DSPs in Mobile Communications Edited by Alan Gatherer and Edgar Ausländer Copyright 2002 John Wiley Sons Ltd ISBNs 0-471-48643-4 Hardback 0-470-84590-2 Electronic 5 The Use of Programmable DSPs in Antenna Array Processing Matthew Bromberg and Donald R. Brown 5.1 Introduction The increasing demand for communications services and the desire for increased data throughput in modern communications systems has fueled research and development into the use of adaptive antenna arrays. Since frequency bandwidth is in short supply and is expensive to acquire the ability to separate users based on their spatial parameters is very attractive for wireless networks. Adaptive antenna arrays offer the ability to increase the Signal-to-Noise Ratio SNR of a wireless communication link while at the same time permit the cancellation and removal of co-channel interference. Because of this an adaptive antenna array can be used to both dramatically increase the data rates of communication links as well as increase the number of users per cell that a wireless network can service. Some authors have reported well over an order of magnitude increase in network capacity 8 . As the computational power of modern Digital Signal Processors DSPs has increased it has become possible to host adaptive array algorithms on these processors. Indeed the DSP has played a critical role in the feasibility of these systems. Many of the blind adaptive array algorithms require branching steps iterative processing or require enough maintenance and flexibility to make hosting them in ASICs difficult. They are ideal however for a sufficiently powerful DSP. With the growing popularity and flexibility of software radios DSPs will continue to enjoy a critical role in the design of these systems. A conceptual block diagram of an adaptive array processor is shown in Figure 5.4. The DSP component of the processor includes much of the processing once the feeds from each antenna are .