中文摘要：

为解决利用通信信号的测向和通信定位综合设计问题,提出了一种载有方向信息的OFDM时空调制技术。该技术采用两副同中心但方向图有偏差的特殊天线阵列发射,使单天线接收机接收的信号是OFDM特性,每个OFDM子载波调制信号载有空间方位信息和数字通信信息,接收机通过解调信号即可通信测向。文中详细介绍了非正交四相和非均匀八相子载波时空调制信号设计思想,阐述了子载波间伪随机码空间调制编码方法,给出了数据信息调解和方位角估计算法。计算机仿真结果表明：在高斯信道下系统的误码性能与普通PSK-OFDM一样,实现了在调制信号设计层面上的数字通信与测向的深度综合。

英文摘要：

To solve the direction-finding with communication signal and the integration of communication and radiolocation, a new space-time OFDM modulation technique is proposed, and the system can transmit azimuth message. The modulation uses the array antenna with two beams in a little different directions, so that the signal received at a single antenna is the OFDM model and the sub-carrier modulation signal is controlled by the azimuth angle and the communication information. The receiver may extract the direction of the receiver relative to the transmitter from demodulating the OFDM signal. This paper presents how to design the signal constellations with non-orthogonal four-phases or non-uniform eightphases, how to encode signal vectors between sub-carriers, how to demodulate data sequence, and how to estimate azimuth from received signal. Simulation results show that the bit error rate with the modulation is the same as that of BPSK-OFDM in a Gaussian channel, and the system is successfully designed to integrate digital communication with direction-finding at the level of signal modulation.