Application: The Walsh words used on the IS-95 forward link are deterministic non-random signals. The average of every product of pairs of different Walsh words of the same length which have the same time origin is identically zero. On the reverse link, the segments of the long PN code used to spread the Walsh symbols transmitted from individual mobile users when taken in pairs do not for all pairs at all times have a zero average. However, over many pairs over long periods of time, the average is zero. Hence, the individual long-code channels on the reverse link may be called near-orthogonal to differentiate them from the forward-link case.

The "short-term" average of the product of Walsh words over a symbol interval on the forward link is zero. The "short-term" average of the product of long PN code segments over a symbol interval on the reverse link is not always zero. However, it is typically small. A much longer averaging time is required for the average of the product of the long-code segments to equal zero with probability near one.

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