Outer code covered synchronous code division multiple access for cable
modem (CM) channels. Outer pseudo-noise (PN) code is employed, along with
orthogonal codes (OCs), to spread CM signals thereby mitigating
inter-code-interference (ICI) effects caused by residual multi-path
propagation within CM communication systems. The added and implemented PN
sequences have relatively good autocorrelation properties (when compared
to the autocorrelation properties of the OCs) that mask the possible bad
autocorrelation and/or cross-correlation properties of the OCs. This
outer-code covered PN coding, along with the OC coding, enables much
better performance in the presence of residual multi-path. The PN code's
added complexity is very minimal as the PN may use the same chip rate of
the orthogonal code while providing for better performance in the
presence of residual multi-path components. In doing so, a relatively
higher system capacity for data throughput may be realized while
providing very limited added complexity to the system.