Enhanced Incoherent Signal Subspace Method for Wideband Direction Finding

Wideband direction finding technology plays a vital role in modern radar, sonar, and wireless communication systems. The traditional Incoherent Signal Subspace Method (ISM) algorithm improves direction-finding resolution through multi-frequency joint processing but suffers from high computational complexity and stringent signal-to-noise ratio requirements.

The enhanced algorithm innovatively introduces a maximum-power frequency selection mechanism: After performing Fourier transform on time-domain signals, analyze the power distribution across subbands Select only the highest-power subband frequency points to construct the spectral density matrix Combine with narrowband direction-finding algorithms to complete direction estimation

This improvement offers dual advantages: Precision enhancement: Maximum-power frequency points contain more prominent signal characteristics, reducing noise interference Efficiency optimization: Single-frequency processing significantly reduces computational load compared to original algorithm's multi-frequency fusion

Simulation data verifies that the enhanced algorithm maintains 100% resolution probability even at lower SNR levels, with smaller azimuth estimation variance. This achievement provides a more practical high-precision direction-finding solution for resource-constrained scenarios (such as airborne equipment and mobile terminals).