New forth-order direction finding algorithm for noncircular signals

Conjugate Extended MUSIC (CE-MUSIC) and MUSIC-like algorithm can be used to estimate the directions of arrival of noncircular signals (e.g. BPSK modulated signals) which are widely used in communication systems. The performance of these two algorithms is not so good because no high order information is used in CE-MUSIC algorithm and no noncircular information is used in MUSIC-like algorithm which is based on forth-order cumulants. In this paper, a new direction finding algorithm called Forth-Order Extended MUSIC (FO-EMUSIC) for noncircular signals is proposed. It can detect more noncircular signals than MUSIC-like and CE-MUSIC algorithms and has better performance (in terms of resolution and angular precision) than MUSIC-like algorithm, and a little better than CE-MUSIC)algorithm. A new FO-EMUSIC algorithm for Uniform Linear Array (ULA) called FO-EMUSIC/ULA which needs much less computation load than FO-EMUSIC is also proposed in this paper. Simulation results show the better performance of FO-EMUSIC than MUSIC-like and CE-MUSIC algorithms.