of bits in the sequence for example perfect u2062 u2062 sequence u2062 u2062 1 u2062 u2062 11 11 11 11 _ 1111 4 but each time a perfect sequence is cyclically shifted by one bit the new sequence is orthogonal with the original sequence thus for example if perfect sequence 1 is cyclically shifted by one bit and then correlated with the original the correlation produces a u201c 0 u201d as in the following example perfect u2062 u2062 sequence u2062 u2062 1 u2062 u2062 11 11 111 1 _ 11 1 1 0 if the perfect sequence 1 is again cyclically shifted by one bit and again correlated with the original then it will produce a u201c 0 u201d in general you can cyclically shift a perfect sequence by any number of bits up to its length and correlate the shifted sequence with the original to obtain a once a perfect sequence of the correct length is selected the first synchronization code is preferably generated in one embodiment by repeating the sequence 4 times thus if perfect sequence 1 is being used then a first synchronization code y would be the following repeating the perfect sequence allows correlator 800 a better opportunity to detect the synchronization code and allows generation of other uncorrelated frequencies as well repeating has the effect of sampling in the frequency domain this effect is illustrated by the graphs in fig1 thus in trace 1 which corresponds to synchronization code y a sample 1002 is generated every fourth sample bin 1000 each sample bin is separated by 1.