A new digital correlator for bandlimited direct sequence spread spectrum signals

A new digital correlator for the reception of bandlimited direct sequence (DS) spread spectrum (SS) signals is described. This correlator could be used in CDMA applications. The correlator is simple in its implementation, using a sign-controlled switch instead of the multiplier and a delta-sigma converter with up/down counter as an integrator. This A/D is simple in its realization, and does not require high-precision elements. Simulation is used to find the effects of the delta-sigma converter parameters on the system performance. Simulation results show that the new correlator, which is much simpler and has a lower cost than the matched filter receiver, has an error probability nearly equal to that of the matched filter for different types of interfering signals and multiuser interference for users using orthogonal signatures.