摘要
水声通信是水下唯一远距离信息有效、可靠传输的方式。水声信道具有严重的多径拓展、多普勒扩展及环境噪声,在此信道下传输会导致正交频分复用(OFDM)系统性能严重恶化。将具有良好的抗多径衰落优点的OFDM系统和对多普勒频偏不敏感的多进制频移键控(MFSK)系统相结合的OFDM—MFSK联合调制方式,无需信道估计与均衡,具有良好的抗噪声性能。在信道条件较好时,在深海垂直信道下,针对OFDM—MFSK系统频带利用率低、通信速率低问题,提出了一种OFDM—MFSK—DPSK(差分相移键控调制)通信方案。该方案利用子载波相位传输附加数据,既不影响OFDM—MFSK系统的稳定性,又能提高系统的通信速率。仿真结果表明,在深海垂直信道下,该方案明显提高了OFDM—MFSK系统的频带利用率和通信速率,且不影响OFDM—MFSK系统传输。
Underwater acoustic communication is the only effective and reliable way to transmit long-distance information underwater.The underwater acoustic channel has serious multipath expansion,Doppler expansion and environmental noise.Transmission under this channel will cause serious deterioration of the OFDM(Orthogonal Frequency Division Multiplexing)system performance.The OFDM-MFDK joint modulation method combines the OFDM system with good anti-multipath fading advantages and the MFSK(Multiple Frequency Shift Keying)system that is not sensitive to Doppler frequency offset,without the need for channel estimation and equalization,and has good anti-noise performance.When the channel conditions are good,such as the deep-sea vertical channel,an OFDM-MFSK-DPSK(Differential Phase Shift Keying)communication scheme is proposed for the problem of low frequency band utilization and low communication rate of the OFDM-MFSK system.This scheme uses the sub-carrier phase to transmit additional data,which does not affect the stability of the OFDM-MFSK system,but can also increase the communication rate of the system.The simulation results show that under the deep-sea vertical channel,the scheme obviously improves the frequency band utilization and communication rate of the OFDM-MFSK system,and does not affect the transmission of the OFDM-MFSK system.
作者
朱师琳
杨蕾
ZHU Shi-lin;YANG Lei(School of Electrical and Electronic Engineering,Wuhan Polytechnic University,Wuhan 430048,China)
出处
《武汉轻工大学学报》
2022年第1期52-57,共6页
Journal of Wuhan Polytechnic University
基金
国家自然科学基金青年项目(51709211).
