The Improved Channel Estimation Algorithm And Simulation Based On MB-OFDM

Ultra wideband(UWB) is one of the key emerging technologies targeted during the recent year, targeting at short-range and low-power communication system. With short-range and low-power, IEEE802.15.3a protocol has great application prospect in smart home, smart building, smart traffic and medical care. There are two main schemes in UWB technology: Multi-Band Orthogonal Frequency Division Multiplexing UWB(MB-OFDM-UWB) and Direct Sequence Code Division Multiple Access UWB(DS-CDMA-UWB). Our research is based on the MB-OFDM-UWB system.The key parts of MB-OFDM system depend on whether it could receive high data and spectrum efficiency, and we often use coherence demodulation method. In this process,the real-time and accurate channel information should be known previously. And then the channel information comes from the prediction of channel estimation. So the performance of the whole communication system largely depends on the accuracy of channel estimation. The optimization channel estimation algorithm is the emphasis of the receiver of MB-OFDM system. It is also the indispensable part in communication system. The superior channel estimation algorithm can obtain the change of the channel frequency response. Through a series of processing, we can get accurate channel information. This paper is based on the premise that we can have a good synchronization and equalization technology. So we need to focus on the improved channel estimation algorithm.The major features of UWB standard channel model(IEEE 802.15.3a) and the basic principles of MB-OFDM-UWB are introduced in Chapter 2. At the same time, we can get four typical channel models. And then the improved channel estimation is introduced based on Pilot-aided in Chapter 3. This paper analyzes two common channel estimation methods. They are LS channel estimation algorithm and MMSE channel estimation algorithm. Because of the algorithm complexity, LS channel estimation algorithm is chosen finally. The results still are affected by noise during the channel estimation. So the wavelet de-noising is added into channel estimation of MB-OFDM system. This paper proposes the improved channel estimation algorithm. After getting the channel frequency response on the pilot tone, the proposed method used Haar tohandle the channel frequency response with wavelet de-noising. And the channel frequency response of the whole band is obtained via interpolation finally. The interpolation algorithm includes linear interpolation, Gauss interpolation, and DFT interpolation. This paper shows the relationship between bit error rate and SNR, and analyses the different performance in Chapter 4. Through the theoretical analysis and the simulation study, the improved method exhibits improved performance. Chapter 5introduces the outcomes in the prospect of our experimental study, and points out the deficiency.