Improved decision directed phase locked loop (dd-pll) for use with short block codes in digital communication systems

Abstract From the Canadian patent

An improved digital decision directed phase locked loop (DD-PLL) for use with short, block codes using phase shifting keying (PSK) modulation. The improvement involves a, conventional digital phase lock loop which is modified to base its loop corrections on the results, obtained by decoding the short block code rather than on a symbol by symbol basis as is, customary in conventional DD-PLLs. The improved method of loop corrections involves, retaining the symbol data pending the decoder's decision derotating the , retained data in, accordance with the decoded result and integrating the derotated data to form a composite, estimator upon which to base the loop correction. In its …