Improved sequential MUSIC

MUSIC (multiple signal classification) is one of the most frequently considered methods for source location using sensor arrays. Among the location methods based on one-dimensional search, MUSIC has excellent performance. In fact, no other one-dimensional method that may outperform MUSIC (in large samples) was known to exist. Our goal here is to introduce such a method, called improved sequential MUSIC (IES-MUSIC), which is shown to be strictly more accurate than MUSIC (in large samples). First, a class of sequential MUSIC estimates is introduced, which depend on a scalar-valued user parameter. MUSIC is shown to be a special case of estimate in that class, corresponding to a value of zero for the user parameter. Next, the optimal user parameter value, which minimizes the asymptotic variance of the estimation errors, is derived. IES-MUSIC is the method based on that optimal choice of the user parameter. Simulation results which lend support to the theoretical findings are included.<>