Parasitic Spectral Lines in High Speed Generation of Binary Maximum Length Sequences

Adding modulo-2 a binary maximum length sequence to its replica delayed by half the maximal length,
N
, results in the same sequence but at twice the bit rate. The error in the spectral density of the resulting sequence which is created by delaying the replica by
(N/2) + \epsilon
instead of
N/2
is examined, and the analytical formulas are derived.