Closed-form for infinite sum in bandlimited CDMA

A closed-form expression is presented for an infinite sum that appears in the theoretical analysis of works in code-division multiple access (CDMA) that assume root-raised-cosine pulse shaping instead of rectangular pulse shaping. The expression derived is sufficiently general to work for arbitrary values of the roll-off factor. The expression is expected to contribute to the simplification of the analysis of CDMA systems with realistic pulse shaping.