Patent ID: 8879674

Claim:
A method comprising: receiving a data communications signal; correlating the received signal with a predetermined bit sequence, at a one instant in time, over a plurality of predetermined frequency offsets; and performing a signal parameter estimation function, to determine a highest correlation value, for the received signal over the predetermined frequency offsets, based on a matrix of final correlation factors; wherein the correlation of the received signal with the predetermined bit sequence, over the plurality of predetermined frequency offsets, comprises: correlating, at the one time instant, each of a number of successive sub-segments of the received signal with a corresponding one of a number of successive sub-segments of the predetermined bit sequence, while disregarding a change in phase factor within each segment of the received signal, to generate a respective correlation factor associated with each sub-segment of the received signal for the one time instant; and coherently combining, for each frequency offset, the correlation factors over the sub-segments of the received signal, to generate a final correlation factor for each frequency offset over the sub-segments of the received signal, by: applying, to each correlation factor, a respective phase shift associated with each of the predetermined frequency offsets, to generate a respective set of frequency adjusted correlation factors for each frequency offset, with each being associated with the respective correlation factor and associated sub-segment of the received signal; and combining, for each frequency offset, the frequency adjusted correlation factors of the respective set, to generate the final correlation factor for each frequency offset over the sub-segments of the received signal, resulting in the matrix of final correlation factors over the predetermined frequency offsets, and wherein the correlation of the received signal with the predetermined bit sequence is further performed over a plurality of instants in time, resulting in a matrix of final correlation factors over the predetermined frequency offsets and over the instants in time, and wherein the correlation of the received signal with the predetermined bit sequence, over the plurality of predetermined frequency offsets and over the plurality of instants in time, is reflected as: c j , k = ∑ l ⁢ ⁢ ⅇ - ⅈ ⁢ ⁢ 2 ⁢ π ⁢ ⁢ klLF ⁢ c j , 0 , l where c j , 0 , l = ∑ n = lL - 1 ( l + 1 ) ⁢ L - 1 ⁢ ⁢ y n + j ⁢ x n * where x reflects a sequence of symbols of the predetermined bit sequence, y reflects a sequence of symbols of the received signal, j reflects a time index, k reflects a frequency index, l reflects the number of sub-segments of the received signal, L reflects a length of each of the sub-segments of the received signal, and F reflects a frequency increment of the predetermined frequency offsets.