Conventional direct-sequence and frequency-hopping spread spectrum systems utilize delay-lock loops to track the timing epoch of pseudonoise codes. These devices perform admirably at high signal-to-noise ratios (SNR), however, they are suboptimal at moderate and low SNR. A correlation loop that employs appropriately filtered pseudonoise signals for the local cross-correlation waveform may have superior performance under these conditions. The performance of this modified correlation loop will be determined by the cross correlation function of the transmitted waveform and locally generated reference signals, along with the statistics of the baseband equivalent noise process. In this work, we find the statistics of the baseband equivalent noise process. The approach is reasonably general and can be applied to a variety of signal structures and pre-correlation filters. In many interesting cases, it is possible to use Central Limit Theorem arguments to show that the equivalent noise is approximately additive, white and Gaussian over the loop bandwidth.
K. L. Kosbar and C. J. Scholten, "Analysis of Baseband Equivalent Noise in a First-Order Correlation Loop Utilizing Filtered Pseudonoise Signals," MILCOM 91: Conference Record : Military Communications in a Changing World, vol. 1, pp. 355-359, Institute of Electrical and Electronics Engineers (IEEE), Nov 1991.
The definitive version is available at https://doi.org/10.1109/MILCOM.1991.258272
1991 IEEE Military Communications Conference, MILCOM '91 (1991: Nov. 4-7, McLean, VA)
Electrical and Computer Engineering
Keywords and Phrases
DLL; PLL; Baseband Equivalent Noise; Central Limit Theorem; Correlation Methods; Filtered Pseudonoise Signals; Filtering and Prediction Theory; First-Order Correlation Loop; Loop Bandwidth; Noise; Phase-Locked Loops; Precorrelation Filters; Thermal Noise
International Standard Book Number (ISBN)
Article - Conference proceedings
© 1991 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.