Simulation Research On MB-OFDM-UWB Wireless Communication System

Ultra-wideband (UWB) wireless communication technology has many good characteristics, such as high speed, low power consumption, cost advantages and strong anti-interference ability. MB-OFDM-UWB (Multiband Orthogonal Frequency Division Multiplexing UWB) is one of the realization schemes. And the application of MB-OFDM-UWB in short distance and high speed wireless connections is still a new subject, a lot of theoretical problems, simulation, and performance analysis of MB-OFDM-UWB should be studied in detail.This dissertation provided a complete study of MB-OFDM-UWB technology by theoretical analysis and simulation experiments. Firstly, the main points of MB-OFDM-UWB technology are introduced, and then the principle of the generation of MB-OFDM-UWB signals is analyzed. The generation of OFDM signals in a sub carrier wave is simulated. The frequency spectrum of OFDM signals is studied .The Power Spectrum Density (PSD) of OFDM signals in different sub carrier waves and three MB-OFDM-UWB signals in Group 1 are simulated. After comparison and analysis, the conclusions are reached: the parallel transmission of three MB-OFDM-UWB signals in different frequency band is feasible, so do the transmission of single signal by frequency hopping.The IEEE802.15.3a standard channel model is analyzed. For the four typical channel models: CM1, CM2, CM3 and CM4, the impulse response of them in continuous channel and discrete channel is simulated. The characteristics of the impulse response in the four typical channel models are compared.The basic principles of MB-OFDM-UWB wireless communication system are introduced. According to FCC and IEEE802.15.3a protocol, the transmitter and receiver of the system are designed, including the physical package structure, convolutional encoder and Viterbi decoder, interleave and deinterleave, QPSK mapping and adverse mapping, OFDM modulator and demodulator.The MB-OFDM-UWB system has been simulated on MATLAB7.0 platform, parameters of baseband were strict simulated according to IEEE802.15.3 protocols, channel part adopts the standard channel issued by the channel working group of IEEE, and established the MB-OFDM-UWB system model. Simulation is at the speed of 200Mbps pattern under the condition of setting up each OFDM symbol number for 60. Thought of increasing useful data sub-carrier and raising coding speed or reduce the prefix of circulating and the length of guard interval as well as the training sequence length may raise the utilization rate of frequency band. The simulation results and the system performances are analyzed. The feasibility of the parallel transmission is verified by frequency spectrum of three OFDM signals. The anti-noise ability is analyzed by frequency spectrum of the received signals in different SNR. The bit error rate is studied by the curvilinear of the BER-SNR variation in CM1～CM4 channels. The relationship of the cover range and the system performance is researched by the curvilinear of the cover range and the PER.The useful conclusions are. reached from the simulation data and graph: all indexes accord with the requirement of FCC and the accuracy and feasibility of the theories are verified. At the same time, the fairly good simulation platform and the experimental data for more studies of MB-OFDM-UWB wireless communication system are offered.