The phase-locked loop (PLL) architecture is studied extensively. It is demonstrated that PLLs are optimal structures in terms of minimizing steady-state mean square tracking error (MSE) at high signal-to-noise ratios (SNR). A closely related device, the delay-locked loop (DLL), is useful for estimating the time delay, or phase, of nonsinusoidal signals. Both PLLs and DLLs fall into the general class known as correlation-loop architectures. It is shown that the steady-state mean square tracking error of first-order correlation loops is minimized by varying the locally generated cross correlation function produced by the voltage controlled oscillator. This analysis assists in the design of modified first-order DLLs used for pseudonoise code synchronization in direct sequence spread-spectrum receivers. The optimization is performed for periodic, but otherwise arbitrary, transmitted signals, for systems operating at arbitrary SNR. The optimal reference waveform is produced by passing a replica of the transmitted signal through a linear time-invariant filter
K. L. Kosbar, "Optimized Cross Correlation Waveforms for First Order Correlation Loops," Proceedings of the IEEE Military Communications Conference, 1990. MILCOM '90, Institute of Electrical and Electronics Engineers (IEEE), Jan 1990.
The definitive version is available at http://dx.doi.org/10.1109/MILCOM.1990.117404
IEEE Military Communications Conference, 1990. MILCOM '90
Electrical and Computer Engineering
Keywords and Phrases
PLL; SNR; Correlators; Cross Correlation Function; Cross Correlation Waveforms; Delay-Locked Loop; Direct Sequence Spread-Spectrum Receivers; Filtering and Prediction Theory; First Order Correlation Loops; High Signal-To-Noise Ratios; Linear Time-Invariant Filter; Mean Square Tracking Error; Nonsinusoidal Signals; Optimal Reference Waveform; Optimization; Periodic Signals; Phase; Phase-Locked Loop; Phase-Locked Loops; Pseudonoise Code Synchronization; Radio Receivers; Spread Spectrum Communication; Steady State Error; Time Delay; Voltage Controlled Oscillator
Article - Conference proceedings
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