DS-CDMA system with high resolution timing

Abstract

A method and apparatus for DS-CDMA communication having improved timing resolution. In the transmitter, a signal spread by a first sequence of pulses is generated with pulse shape given by p ⁡ ( t T c ) , where t is time and Tc is the chip period or pulse width. The pulses have an auto-correlation function q ⁡ ( t T c ) . In receiver, a second sequence of pulses with pulse shape given by p ⁡ ( t T c ) is generated. When correlated with the first sequence of pulses the resulting correlation function is proportional to q ⁡ ( t T c ) - q ⁡ ( t T c - 1 ) . This correlation function narrower peaks than the correlation function q ⁡ ( t T c ) , thereby allowing higher time resolution to be achieved. The correlation function is achieved by modification of the transmitter or receiver modulation sequences or by modification of the correlator in the receiver.

Dependencies are inferred from the claim text.