发射二维方向信息的时空调制OFDM通信测向系统

Communication and Direction-Finding System of Space-Time OFDM Modulation with 2-Dimensional Directional Information

通信与测向是现代电子系统中的两项重要技术,为了设计通信与测向综合发射源,本文提出一种发射信号载有二维方向信息的空间调制OFDM通信测向方案.其思想是利用间距大于半个波长的平面8元天线阵列,二元一组分组激励发射,使合成电磁场是一个被方位角和仰角信息调制的OFDM信号,单天线接收机只需解调信号就可以实现数字通信和测向任务.文中阐述了二维空间调制原理,选择了调制信号星座,设计了信号状态的差分编码结构,给出了单天线接收测向和数字信息解调算法.最后,通过对高斯信道下通信误码率和测向精度的仿真,证明了系统设计的有效性.

Communication and direction-finding play important roles in modern electronic systems. In order to design transmit sources for integrated systems of communication and direction-finding, we propose a new space modulation OFDM technique, with which the system can transmit microwave signal carrying 2-dimensional directional information. The main idea is that the eight element antennas spaced in more than half wavelength are divided into four arrays to produce multi-beams, so that the received OFDM signal has been modulated by azimuth angle and elevation angle. The single-antenna receiver could accomplish communication and direction-finding by demodulating signals in the beam-space. This paper presents how to choose the signal constellations of space-time modulation ,how to design the scheme of the differential coding, and how to develop the algorithm of demodulating and estimating directional information. The performances of bit error rate and direction-fmding in Gaussian channel are investigated. Simulation results show that the design of system is successful.