A method and apparatus are disclosed for modulating a communication signal
in a CDMA environment using orthogonal N by N Hadamard spread spectrum
codes. Orthogonal spreading codes are used that have lengths that are not
a power-of 2 to provide additional channel variability for various
multimedia applications and increase the flexibility of the number of
channels/bandwidth relationship. The Hadamard codes are multiples of 4
(4n) and demonstrate a good cross-correlation property, making them very
useful in the flexible design of CDMA systems. A transmitter encodes each
of N data streams (N not being a power of 2), to be transmitted using a
4n codeword, N.sub.i. The received signal is passed through a filter
matched to the characteristics of the appropriate codeword, N.sub.i, and
PN spreading sequence.