Implement Wavelet Packet Transform-based Multicarrier Modulation Algorithm On DSP

Wireless mobile communication provides a more efficient way of message transmission for moving subscribers, with flexibility in both time and space. However, the complex wireless channels and limited frequency spectrum source put forward stricter requirement to the wireless transmission. The select and design of wireless modulation/demodulation plays an important role in bettering wireless mobile communication performances. CDMA, widely employed in the third generation wireless communication system, however, could not meet the increasing needs of high-quality video and multimedia services. The forth generation prefers to using multicarrier modulation technique in order to provide the wide-band, high-speed rate services. As a result, multicarrier modulation technique became a hotspot in these years. The purpose of this paper lies on researching a new modulation technique— WPT-MCM (Wavelet Packet Transform- based MultiCarrier Modulation). First of all, based on the wavelet and wavelet packet theory, the performance and the superiority over the OFDM are presented. At the same time, a new modulation approach, which can be implemented by fast algorithm, is discussed and analyzed. This paper also proves the possibility of this new method.Then the structural and the functional features of TMS320C6701 are presented in detail. Based on it, the software approach and the procedure of WPT-MCM are provided. Meanwhile, some main techniques in the software design are discussed. After that, under the consideration of the tradeoffs between processing speed and system performance, optimized solutions of some parts are provided. At last, through the implement of the algorithm on TI's TMS320C6701 EVM and the modeling and simulating with MATLAB, which using AWGN channel, Rayleigh and channels corrupted by tone and impulse interference, the good performance of WPT-MCM is demonstrated and further explored.The analysis of the experiment results indicates that the software implementation scheme of this system is qualified to accomplish the task of WPT-MCM. It also proves the WPT-MCM has unique advantage and great potential and worth of further researching.