The Performance Analysis Of UWB Wireless Communications System

The Ultra-wide band (UWB) is a new technique for wireless communication. Since it modulates directly on the impulse of steep positive edge and negative edge, the UWB signal has GHz wide frequency band. Simultaneously, it has such advantages as the insensitivity to channel fading, low density of signal's power spectrum, low acquisition, low complexity of the system, the ability to have the centigrade positioning accuracy, etc. Therefore, this technique plays an extremely potential role in the short-range radio communication and becomes one of the hot research topics. Since the performance analysis is extremely important to the research on the system of UWB wireless communications, this paper mainly analyzes the performance of the UWB system.In the system of UWB wireless communications, inter-symbol interference (ISI) and multi-user interference (MUI) are the main reasons that affect the system performance. The ISI is mainly caused by the dense multi-path, and the MUI caused by the multi-users in the same frequency domain.This paper studies the performance of the system of UWB wireless communications in the multi-user environment. First, the characters, application and future development of the system of the UWB wireless communications are introduced in details. Second, this paper introduces the three-kind normal modulation models, namely Time Hopping Pulse Position Modulation (TH-PPM), Time Hopping Pulse Amplitude Modulation (TH-PAM) and Direct Sequence Ultra Wide Band (DS-UWB). The corresponding demodulation theories are also recommended. Third, based on the hypothesis of Standard Gaussian Approximation (SGA) in the environment of multi-users, this paper derives the bit error rate (BER) expressions. The comparison is made of the reception techniques and multi-path performances of TH-PPM, TH-PAM and DS-UWB. The modulation modes of TH-PP and TH-PAM are further compared in such three aspects as power control, information channel parameters and modulation parameters and the further discussion is also made on the multi-path performance of the system under the given condition. It is shown by theoretical analysis and computer simulation that the three modulation modes of UWB wireless communication have the similar BER expression in the case of white Gaussian noise. If only singular user system...