Algorithm design and implementation of a spread spectrum system with Space-time coding and cyclic shift orthogonal keying

• Main Authors: Kuan-Lin Tung, 董冠麟
• Other Authors: Juinn- Horng Deng
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/35058445346060472307

碩士 === 元智大學 === 通訊工程學系 === 98 === This paper proposal is designed by the advanced modulation and coding techniques, which can be used for the future satellite broadband communications. CDMA is adopted in order to obtain the code gain ,to resist the long distance transmission. First, the earth station will transmit the encoded data via RS encoder and Convolutional encoder. These coding schemes will correct the distributed and block errors, which will render the proposed system to acquire the coding gain. Next, a novel M-ary mapping technique is proposed to enhance the transmission data rate. The M-ary different bits can be mapped by a cyclic spreading code. And the mapping scheme will incur higher data rate than the conventional CDMA system. The spreading code will be designed to involve the MSK modulation technique, which will limit the transmitted signal with constant envelope and let the utilization efficiency of power amplifier to achieve optimal. To realize multi-rate performance, we will adopt the different size spreading codes to spread the mapped data. To enhance the spectral efficiency, the multiple antenna system will be proposed to realize the space-time coding techniques. Likewise, the cyclic prefix technique will be proposed to combat the multipath interference. Finally, we use Xilinx System Generator IP Code to design the model of system, and download in FPGA chip, and the BER performance of the proposed transceiver will be simulated and analyzed under the AWGN and fading channels.