Signal Toolkit - rcosdesign

Function File: b = rcosdesign (beta, span, sps)

Function File: b = rcosdesign (beta, span, sps, shape)

Design a raised cosine FIR filter.

The filter coefficients b are returned as a row vector of length sps * span + 1. The roll-off factor beta controls the excess bandwidth and must be in the range [0, 1]. The filter is truncated to span symbol periods, with sps samples per symbol.

The optional argument shape selects the raised cosine variant:

"sqrt" (default)

Square-root raised cosine filter. When two such filters are used in cascade (e.g., one at the transmitter and one at the receiver), the combined response matches a normal raised cosine filter.

"normal"

Normal (full) raised cosine filter. This filter satisfies the Nyquist criterion for zero intersymbol interference, with zero crossings at multiples of the symbol period.

See also: gaussdesign.