| 摘要 |
Receiver 200 receives multiple multi-tone OFDM-like signals from respective transmitters 100 with known locations, each multi-tone signal having sub-carriers modulated with a pseudo-random noise code; a coarse estimate of a time of arrival of one or more of the sub-carriers is adjusted in accordance with a code correlation function (S302, Fig.11); a precise estimate of said time of arrival to align a slope at least two of the sub-carrier phases of the multi-tone signals is adjusted in accordance with a phase correlation function and the coarse estimate (S304, Fig.12); and receiver location or its range to a transmitter is estimated there-from (S306, Fig.11). The range or location is adjusted (S352, Fig.16B) according to multipath phase compensation data which compensates for a multipath phase error in a subcarrier phase associated with a multipath-impacted signal. This is based on lengths of a direct path signal and a a multipath-impacted signal that are determined (S354, Fig.14B) through observed signals or observed signal vectors of the receiver. |
