Decomposition technique for acquiring combined pseudorandom-noise signals

A new technique for fast acquisition of pseudorandom-noise (p.r.n.) signals is derived. By considering that the period of a long combined p.r.n. sequence is equal to the product of the periods of its component sequences, we found that phase synchronisation can be achieved much easier after directly decomposing the received p.r.n. sequence into its component sequences, thus eliminating the sequential search required by the existing methods. Advantages of the proposed technique are: (a) it is easy to implement, (b) there are low probabilities of false alarm and false dismissal, and (c) in the minimising of the correlation time. It could not only significantly improve the existing p.r.n. ranging and tracking systems, but also could strengthen and simplify spread-spectrum communication systems, especially in the secure-code generators and logical-minimisation areas. Examples are presented and discussed.