Research On Transmission Schemes Of MIMO MB-IR-UWB System

Due to emergence of new media, such as wireless local area network and home entertainment network, demand for high speed communication has become higher. The Ultra Wideband technology provides a solution to realize high speed communication. However,conventional Impulse-Radio-UWB system performs poor in spectrum flexibility and cannot provide capacity of parallel data transmission, which restricts performance of UWB system.To solve this problem, a novel Multiband-IR-UWB system based on Prolate Spheroidal Wave Function waveform is proposed and applied. MB-IR-UWB system based on PSWF waveform divides 3.1GHz-10.6GHz into 15 sub bands evenly, thus providing frequency resource for parallel data transmission. Meanwhile, more space resource is available by introducing Multiple-input Multiple-output technology into the system.In order to achieve optimal deployment of space-time-frequency domains of MIMO MB-IR-UWB system, space-time-frequency code is applied to measure the diversity and multiplexing gain of the system. There are two kinds of STFC scheme studied in this research.The DSTFCs, designed for improving the system reliability, is mainly used to improve the Bit-Error-Ratio performance of MIMO-MB-IR-UWB system. As a result,system's throughput would become lower but its receiver can be quite simple. The Power Adaptive Cycle scheme designed to enhance the system throughput can achieve full space-time-frequency multiplexing gain, but the serious interference in MIMO MB-IR-UWB system based on PAC would load to quite much complexity in the receiver detection algorithm.In this paper, we propose an optimal transmission scheme of MIMO MB-IR-UWB system. The working mode of the MIMO MB-IR-UWB system is analyzed first and four available working modes-MIMO IR-UWB mode, lb×Nt mode, Lb×Nt mode and 1b×1 mode are given according to the different rules of sub bands selection. Based on that,taking the BER performance, theoretical maximum communication data rate, and the complexity of receiver algorithm into consideration, five optimal transmission scheme of MIMO MB-IR-UWB system, with three of them basing on DSTFCs and two basing on PAC, was analyzed and compared.