Simplified calculation of mobile location using scatter information

Scatter information can be used to overcome the problem of mobile localization in non-line-of-sight conditions. Since many redundant parameters, such as scatterer locations and Doppler parameters are involved in the nonlinear localization equations, it is difficult to obtain the solution to mobile position. We reduce the numbers of measurements and redundant parameters in the nonlinear localization equations by taking advantage of an inherent symmetric Doppler property of a special set of measurements. Incorporating this property with time-delay and direction measurements corresponding to multipath signals with the same Doppler-shifted frequency, a novel closed-form solution to mobile location is proposed. Numerical results are provided to show that it is less insensitive to the scatter environment than ordinary localization methods.