Primitive Polynomials for Iterative Recursive Soft Sequential Acquisition of Concatenated Sequences

An iterative initial sequence acquisition technique is proposed for the pseudo-noise signal derived from a pair of m-sequences used for generating the concatenated sequence, which relies on the soft-in-soft-out detection to improve the acquisition performance. This recursive soft sequential estimation technique has a linearly increasing complexity with the number of chips in the concatenated sequence. Receiving as few as S consecutive chips of a (2
^S
- 1)-chip sequence is sufficient for the local concatenated-sequence generator of the receiver to synchronize. Hence, this initial synchronization technique is eminently suitable for long m-sequences and concatenated sequences. Another key result is the comparison of m-sequences and concatenated sequences regarding the acquisition time. It is also observed that low-order primitive polynomials (PPs) achieve better performances than higher-order polynomials for both the m-sequences and concatenated sequences. When considering PPs having a higher number of taps, the exploitation of concatenated sequences is capable of achieving in excess of 3-dB signal-to-noise ratio gains over m-sequences.