AL-OFDM和SM-OFDM空频分组码信号盲识别方法

针对空频分组码-正交频分复用(space-frequency block codes with orthogonal frequency division multiplexing, SFBC-OFDM)信号盲识别问题,提出了一种基于互相关函数的空频分组码信号盲识别方法。首先根据不同SFBC-OFDM元素的相关性,推导了发射信号端信号的相关特性;然后根据发射端信号的相关性,推导了接收端SFBC-OFDM信号的相关特性;最后提出了基于峰值检测的识别算法。仿真结果表明,该算法在较低的信噪比(0 dB)下正确识别概率达到95%,且不需要预先知道信道信息、噪声信息和调制信息。该算法在不同调制方式、时延和频率偏移下正确识别概率在90%以上,能够应用于认知无线电、频谱监控等工程领域中。

Blind signal recognition method of AL-OFDM and SM-OFDM space-frequency block codes

To solve the problem of the space-frequency block codes with orthogonal frequency division multiplexing (SFBC-OFDM) blind signal recognition, a space-frequency block codes signal recognition method based on correlation function is proposed. Firstly, the correlation characteristic of transmit signal is obtained based on correlation among the different SFBC-OFDM elements. Then, the correlation characteristic of the receive signal is obtained based on the correlation among the transmit signals. Finally, the automatic signal recognition algorithm based on the peak test is proposed. The simulation result shows that the recognition probability of the proposed algorithm is 95% at a low signal to noise ratio (0 dB), and does not need channel coefficient, noise information and modulation types, and the correct identification probability is over 90% under the different modulation scheme, time offset and frequency offset. It can be applied in the engineer field such as cognitive radio systems, spectrum surveillance, and so on.