Design and VLSI implementation for a WCDMA multipath searcher

The third generation (3G) of cellular communications standards is based on wideband CDMA. The wideband signal experiences frequency selective fading due to multipath propagation. To mitigate this effect, a RAKE receiver is typically used to coherently combine the signal energy received on different multipaths. An effective multipath searcher is, therefore, required to identify the delayed versions of the transmitted signal with low probability of false alarm and misdetection. This paper presents an efficient and novel WCDMA multipath searcher design and VLSI architecture that provides a good compromise between complexity, performance, and power consumption. Novel multipath searcher algorithms such as time domain interleaving and peak detection are also presented. The proposed searcher was implemented in 0.18 /spl mu/m CMOS technology and requires only 150 k gates for a total area of 1.5 mm/sup 2/ consuming 6.6 mw at 100 MHz. The functionality and performance of the searcher was verified under realistic conditions using a channel emulator.     

TOPICS IN OPTICAL COMMUNICATIONS - Fundamentals and Challenges of Optical Multiple-Input Multiple-Output Multimode Fiber Links

In this article we discuss the application of MIMO processing to multimode fiber links. MIMO processing is shown to increase the information capacity of communication links linearly as the minimum number of transmitters/receivers increases. The fundamentals of optical MIMO fiber links are presented, and the promises and challenges of such systems are elaborated