Mb - Ofdm Uwb System Research Of The Analog Front-end Non-ideal Factors

Ultra-Wideband (UWB) technology is a promising wireless transmission solution in personal area networks due to its high data-rate, low-power and high security features. Meanwhile Orthogonal Frequency Division Multiplexing (OFDM) is seen as the core technology of physical layer in future wireless communication system. Milti-Band OFDM (MB-OFDM) standard has been approved by the ISO and became the first UWB standard in the world, which has a broad market prospect and attracted attention from both the academic and the industry.However, OFDM technology is sensitive to synchronization errors, such as Carrier Frequency Offset (CFO) and Sampling Frequency Offset (SFO). Besides, I/Q mismatch exists both in transmitter and receiver. MB-OFDM UWB system suffers a lot from these imperfections. Traditional algorithms either deal with some of the imperfections or relied on iterative or non-linear methods, which require high computational power and result in high hardware cost.This thesis describes the evolution and the basic theory of MB-OFDM UWB system, and also analysis the effects caused by imperfections, and then introduces the proposed joint estimation and compensation scheme which works in the frequency domain.This algorithm is mainly consisting of CORDIC and complex divider operations, which is convenient for hardware implementation. According to standard of the physical layer packet structure in MB-OFDM UWB systems, the thesis gives the hardware-reused architecture and the timing sequence planning, and designs the CORDIC and complex divider module. Mode1S im simulation results show that both the modules work in high calculation accuracy. Simulation results show that this algorithm works effectively in the case of frequency selective I/Q mismatch. The packet error rates in different channels are closer to ideal cases.