Patent ID: 7151793

Claim:
A method for performing the operations for synchronizing a positioning receiver with a received code-modulated spread spectrum signal, the method comprising: using at least one reference code, which reference code corresponds to a code used in the modulation, acquiring the frequency shift of the received signal and the code phase of the code used in the modulation, taking samples from the received signal for forming at least two sample vectors, forming a first Fast Hartley transform on the basis of said reference code, and a second Fast Hartley transform on the basis of each sample vector, performing a multiplication between the first Fast Hartley transform formed on the basis of said reference code and the second Fast Hartley transform formed on the basis of each sample vector, performing an inverse Fast Hartley transform on each multiplication result, and acquiring the frequency shift and code phase on the basis of the inverse Fast Hartley transforms of the multiplication results, wherein in said sample vector formation, correlation and analysis are repeated for forming at least two coherent search matrixes, and a summing is also performed in the method, in which summing an incoherent search matrix is formed by summing incoherently the values of the equivalent elements of the coherent search matrix formed at each time of repetition, and said incoherent search matrix is used in said acquisition for acquiring the frequency shift and code phase.