摘要
针对全球移动通信系统(GSM)的安全机制不能实现端到端安全通信问题,提出了一种低复杂度基于脉冲调制的数据传输方案及优化方法。分别设计了基于脉冲位置调制及脉位结合极性调制的类语音信号,给出了基于跳时脉冲的帧同步方法。搭建了基于脉冲调制的GSM语音信道数据传输仿真平台,分析比较了不同调制阶数和不同自适应多速率编码(AMR)码率下系统的性能。为了提高系统可靠性,引入卷积码进一步降低了系统误码率。仿真结果表明,4阶脉冲调制最适用于语音信道,所提脉冲调制方法与传统低复杂度频移键控(FSK)调制方式误码率近似,但传输速率高,且提出的脉位结合极性调制进一步提高了传输速率,总提高比例达到36%。
Aiming at the problem that the security mechanism of Global System for Mobile Communications （GSM） can not realize end-to -e n d security communication,a data transmission scheme and optimization method based on pulse modulation with low complexity is proposed. Speech-like signals based on Pulse Position Modulation and Pulse Position Polarity Modulation schemes are designed respectively. The syn-chronization scheme based on time hopping pulse modulation is provided. A simulation platform of data transmission over GSM voice channel is bui l t,and the system performances of different modulation level and adaptive multi-rate （AMR） codec with different coding rate are compared and analyzed. In order to fu r-ther reduce the system error ra te, the convolutional code is introduced. Simulations show that the pulse modulation with order 4 is most suitable for voice channel. The proposed pulse modulation scheme is simi-lar to the traditional Frequency Shift Keying（FSK） modulation scheme with same b it error rate（ BER） but higher transmission rate,and the proposed pulse position combined with polar modulation further improves the transmission rate,with a total improvement rate of 3 6 % .
出处
《电讯技术》
北大核心
2018年第2期152-156,共5页
Telecommunication Engineering
基金
国家自然科学基金资助项目(61402044)
北京市科技新星计划项目(Z161100004916086)
北京市优秀人才资助计划青年拔尖项目(2016000026833ZK08)
北京市属高校"青年拔尖人才培养计划"(CIT&TCD201704065)
