Applying Voice Encoded Multiplexing in DAB System

• Main Authors: Chia-Hung Chen, 陳嘉宏
• Other Authors: 林信標
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/s6xzsu

碩士 === 國立臺北科技大學 === 電腦與通訊研究所 === 94 === In wireless communications, bandwidth is the most important resource. In the future, how to reduce the usage of radio frequency bandwidth will be an important issue to be discussed. A new signal process method is proposed to be used in wireless communication system and which could mix multi-signals in a narrowband bandwidth. If this method is applied in DAB system, the number of programs would be increased with the same bandwidth. In this thesis, not only the software simulation but also the hardware implementation is presented to prove the feasibility of this proposed signal process method called “voice encoded multiplexing”. In the simulation results, 5 voice signals can be mixed in a 1KHz bandwidth, and the encoded signal of each voice signal has its own orthogonal property. In DAB system, 6 programs most can be transmitted in 1.536MHz bandwidth. However, by applying voice encoded multiplexing in DAB system, 5 programs can be multiplexed in the bandwidth of one program, and the BER performance could approach 10-5 when the SNR is 12dB which is the same as original DAB system. For DAB system, per 1.536MHz bandwidth of one license, we could transmit 30 programs, and the total earnings was 5 times of original DAB system.