端到端语音加密通信系统中,密文语音数据在移动通信网中可能面临的失真、失码等问题,利用通用滤波多载波(Universal Filtered Multi Carrier,UFMC)技术的类语音调制特性可实现信道的抗压缩传输.为进一步增强其抗干扰性能,克服同步偏差的影响,提出一种UFMC类语音时频联合同步方案.该方案首先将Zadoff-Chu序列搭载至UFMC类语音系统的合适载波频段上合成新型类语音同步信号,而后根据UFMC类语音算法滤波器长度应为奇数的特点,构造出具有重复结构的类语音同步信号,使其可凭借自身冗余特性先后完成对时延、频偏的估计.在AMR-NB12.2kb/s声码器模型下的仿真结果表明:所提同步方案能精准定位解调起点,可较好满足UFMC类语音系统同步需求.
Design and Implementation of Synchronization Scheme for UFMC Voice-like System
In end-to-end voice encryption communication systems,encrypted voice data may suffer from problems such as distortion and code loss in mobile communication networks.Utilizing the voice-like modulation characteristics of the Universal Filtered Multi Carrier(UFMC)technology could achieve channel anti compression transmission.To further enhance the anti-jamming capability and overcome the impact induced by synchronization bias,a UFMC voice-like time-frequency joint synchronization scheme is proposed,where first Zadoff-Chu sequence is loaded into the suitable carrier frequency band of the UFMC voice-like system to synthesize a new voice-like synchronization signal,and then a voice-like synchronization signal with repetitive structure is constructed according to the characteristic that fil-ters in UFMC voice-like algorithms have odd filter length,leading to successive time delay and frequen-cy offset estimation depending on its own redundancy characteristic.Simulation results performed in AMR-NB12.2kb/s vocoder channel model show that our proposed synchronization scheme could accu-rately locate the demodulation starting point and well satisfy the synchronization requirements of UFMC voice-like systems.
end-to-end encryptionvoice-like modulationuniversal filtered multi-carriersymbol tim-ing synchronizationcarrier frequency synchronization
万方数据
维普
