Abstract: The disclosure relates to a method and an apparatus for locating a mobile device in a network system. For each pair of anchor stations, a receiver channel delay difference of receiving times of a first signal transmitted by a different anchor station and received at the anchor stations is determined. This receiver channel delay difference is used for compensating time difference of arrival among the mobile device and the pair of anchor stations. The compensated time difference of arrivals among the mobile device and the pair of anchor stations are used to determine the position of the mobile device.

Abstract: This application discloses a downlink channel reconstruction method and apparatus. In one embodiment, the method includes: sending, by a base station, multiple different weighted pilot signals to a terminal, where each of the weighted pilot signals includes a product of a pilot signal and a weighting matrix; receiving, by the base station, multiple different optimal code words returned by the terminal, where each of the optimal code words is obtained based on a channel estimation of a weighted pilot signal; and reconstructing, by the base station, a downlink channel according to the multiple different optimal code words. According to the foregoing method, a quantization error can be reduced, so that a beam direction of a reconstructed channel correctly points to the terminal.

Abstract: This application discloses a downlink channel reconstruction method and apparatus. In one embodiment, the method includes: sending, by a base station, multiple different weighted pilot signals to a terminal, where each of the weighted pilot signals includes a product of a pilot signal and a weighting matrix; receiving, by the base station, multiple different optimal code words returned by the terminal, where each of the optimal code words is obtained based on a channel estimation of a weighted pilot signal; and reconstructing, by the base station, a downlink channel according to the multiple different optimal code words. According to the foregoing method, a quantization error can be reduced, so that a beam direction of a reconstructed channel correctly points to the terminal.