Robust adaptive recovery of spread-spectrum signals with short data records

Short Data Record Adaptive Filtering: The Auxiliary-Vector Algorithm

“…. are all constrained to be orthogonal to v, orthogonality among the auxiliary vectors is not imposed [20,21]. This is in sharp contrast to previous work that involved filtering with up to L − 1 orthogonal to each other and to v vectors [22][23][24], where L is the data input vector dimension.…”

Adaptive Antenna Array Receivers for Spread-Spectrum Signals in Non-Gaussian Noise

“…In particular, the nonlinear receiver front end adapts itself to the unknown prevailing impulsive noise environment, while the adaptive linear tapweight filter that follows the nonlinearly processed chip samples combats effectively the unknown SS interference. This article enhances our previous work in [9,10] in the following aspects. A narrowband adaptive antenna array is employed for joint space-time (S-T) disturbance suppression under a generalized multipath signal model that includes chip-rate random impulsive disturbance with direction of arrival changing at the chip rate.…”

“…In [9,10] adaptive receivers are developed that are composed of a vector of adaptive chip-based nonlinearities followed by an adaptive linear tapweight filter. The structures proposed in [9,10] tap the relative merits of both nonlinear and linear signal processing and exhibit superior bit-error-rate (BER) performance in the presence of combined impulsive and unknown SS interference. In particular, the nonlinear receiver front end adapts itself to the unknown prevailing impulsive noise environment, while the adaptive linear tapweight filter that follows the nonlinearly processed chip samples combats effectively the unknown SS interference.…”

“…Signal detection in the presence of impulsive channel noise has been considered extensively in the past (for example [1][2][3][4][5] and references therein), while detection of a direct-sequence spread-spectrum (DS-SS) signal under similar channel conditions has been studied in [6,7] and more recently in [8][9][10]. Receiver proposals in [6] involve the use of either a conventional signature matched filter or a majority-vote receiver (hard-limiter nonlinearity per chip followed by signature matched filtering).…”

“…To handle unknown SS interference, a minimax subspace approach that relies on eigendecomposition of the impulsive-noise corrupted input autocorrelation matrix is also proposed in [8]. In [9,10] adaptive receivers are developed that are composed of a vector of adaptive chip-based nonlinearities followed by an adaptive linear tapweight filter. The structures proposed in [9,10] tap the relative merits of both nonlinear and linear signal processing and exhibit superior bit-error-rate (BER) performance in the presence of combined impulsive and unknown SS interference.…”