Method and device for determining downlink beam forming weight vector

Abstract

The invention discloses a method and a device for determining a downlink beam forming weight vector. The method comprises the following steps: receiving a pilot signal sent by a terminal so as to estimate the frequency offset of the terminal; judging whether the frequency offset is smaller than preset frequency offset; if the frequency offset is smaller than the preset frequency offset, determining a weight vector according to a first mode, namely acquiring a first time interval, judging whether the first time interval is smaller than a first threshold value, if so, directly determining the downlink beam forming weight vector by using an SRS (sounding reference symbol), and otherwise, determining the downlink beam forming weight vector by using a PMI (pre-coding matrix indicator); if the frequency offset is not smaller than the preset frequency offset, determining the weight vector according to a second mode, namely acquiring a second time interval, judging whether the second time interval is smaller than a second threshold value, if so, directly determining the downlink beam forming weight vector by using the PMI, and otherwise, determining the downlink beam forming weight vector by using the SRS. A speed factor and a time factor are taken into overall consideration, and a weight vector calculation mode suitable for a current scene is selected in real time, so that the calculation accuracy of the weight vector and the beam forming effect can be improved, and the downlink performance and cell capacity of a user are improved.

Description

technical field [0001] The present invention relates to the field of communication technologies, in particular to a method and device for determining downlink beamforming weight vectors. Background technique [0002] Beamforming is mainly used to compensate signal fading and distortion caused by factors such as space loss and multipath effects during wireless propagation, and at the same time reduce interference between co-channel users. [0003] The core of the beamforming technology is to determine the weight value of the weight vector (that is, the weight vector), and apply the weight vector directly to the downlink transmission signal, so that the main lobe of the smart antenna pattern is aligned with the desired signal, and the zero point is aligned with the interference signal, thereby Ensure that the receiving end can accurately separate the desired signal from the received signal. [0004] There are two ways of determining the weight vector in the prior art, which w...

AI Technical Summary

Problems solved by technology

In this method, when the terminal selects the PMI, it selects elements similar to the current downlink channel information from a certain set of elements, so that there may be a certain quantization error between the PMI information and the real downlink channel information.

In addition, if the time when the base station receives PMI information is far from the time when the base station uses the weight vector to perform beamforming, the accuracy of the weight vector determined based on the PMI information will also be low, which will affect the beamforming effect.

Images