Efficient Differential Coherent Accumulation Algorithm for Weak GPS Signal Bit Synchronization

An efficient differential coherent accumulation algorithm for weak GPS signal bit synchronization is presented. With this algorithm, every two successive 1ms coherent integration values are processed with the differential coherent first, whereafter these differential coherent values are accumulated according to 20 navigation data bit boundary candidates as the decision variable. The navigation data bit boundary candidate corresponding to the minimum of these decision variables is determined as the navigation data bit boundary position to achieve bit synchronization. Compared with previous differential coherent accumulation algorithm, this algorithm shows a theoretical reduction in computational load by approximately sixfold.