An autocorrelation is computed on the inphase and quadrature data, using a standard pulse pair algorithm . The output of the standard pulse pair algorithm are the zeroth and first lag of the complex autocorrelation function: R_{n}(0) and R_{n}(T_{s}). The total received power is defined as: P_{n} = R_{n}(0), and the resultant vector of the lag one autocorrelation is defined as: R_{n}(T_{s}) = A_{n} + jB_{n}; where n denotes the frequency number (1 £ n £ 5). The autocorrelation is performed simultaneously on all transmitted frequencies. Vector addition is performed across the frequencies, yielding resultant vector R(T_{s}) , as given by equation 1: