Spreading code acquisition for direct sequence spread spectrum signals

An apparatus for acquiring a phase of a complex spreading code from a direct sequence spread spectrum (DSSS) signal, the DSSS signal comprising a data signal spectrally spread with the complex spreading code, the apparatus comprising:

• a memory for storing at least a portion of a sampled DSSS signal obtained from the DSSS signal by sampling thereof at a sampling rate at least equal to a chip rate of the spreading code, the sampled DSSS signal comprising an in-phase signal composed of in-phase signal samples, and a quadrature signal composed of quadrature signal samples;
• a differential product (DP) processor operatively coupled to the memory for generating a sequence of n bipolar DP values from the in-phase and quadrature signals using a DP operation, the bipolar DP values having a sign that is generally independent on the data signal;
• a decoder operatively coupled to the DP processor for receiving the sequence of n bipolar DP values, and for obtaining therefrom a codeword of a linear block code (n, kc), wherein k is a length of a spreading code generator (SCG) for generating the spreading code, and n is a positive integer greater than k, and wherein the linear block code (n, kc) is defined by the SCG and the linear differential product operation;
• and,
• a state computer operatively coupled to the decoder for receiving the codeword and for computing therefrom an SCG state estimate based on a pre-computed characteristic of the linear block code (n, kc).