Analysis of digital tanlock loop with adaptive filtering

The authors consider the discrete-time analysis of adaptive filtering in a digital tanlock loop (DTLL) for tracking a wide variety of input signals. The detection circuit (DTLL) uses a linear phase error detector which is the tan function with in-phase and quadrature samples of the received signal. Using a uniform multisampling structure gives a wide pull-in range and fast acquisition performance. In order to maintain optimum detection, adjustments in the filter coefficients are needed. The problem is solved when the performance is increased by using a least mean square adaptive detection filter