Method and system for acquiring information of uplink channel and downlink channel

Abstract

The invention provides a method for acquiring information of a downlink channel, comprising the following steps: a terminal sends a detection pilot frequency and downlink interference information to abase station; the base station acquires uplink channel status information according to the detection pilot frequency so as to acquire equivalent downlink channel status information, and acquires downlink channel relevant information according to equivalent downlink channel status information and downlink interference information. The invention provides a system for acquiring downlink channel information, and also provides a method for acquiring uplink channel information. The method comprises the following steps: the base station sends the uplink interference channel status information and adownlink pilot frequency to the terminal; the terminal acquires downlink channel status information according to the downlink pilot frequency so as to acquire equivalent uplink channel status information, acquires uplink channel relevant information according to the equivalent uplink channel status information and uplink interference information, and sends the acquired uplink channel quality information to the base station. The invention also provides a system for acquiring the uplink channel information, and acquires channel information by utilizing channel reciprocity, thus reducing uplink expenditure.

Description

technical field [0001] The present invention relates to the field of digital communication, in particular to long-term evolution / advanced long-term evolution (LongTerm Evolution / Long Term Evolution-Advanced, referred to as LTE / LTE-A) system in time division duplex (Time Division Duplex, referred to as TDD) mode uplink And a downlink channel information acquisition method and system. Background technique [0002] In the LTE / LTE_A system, in order to perform downlink scheduling and resource allocation, the base station needs to obtain relevant information about the downlink channel, which includes pre-coded indicator information (Pre-coded Matrix Indication, referred to as PMI), channel quality information (Channel Quality Information, referred to as CQI) and rank indication information (Rank Indication, RI for short), etc. To this end, the base station sends a common reference symbol (Common Reference Symbol, CRS for short) / channel state information pilot signal (Channel Sta...

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Problems solved by technology

[0004] One of the main problems of the acquisition method of downlink channel related information is that the uplink feedback overhead is relatively large, especially in LTE-A, for Co-ordinated Multi-Points (CoMP for short) transmission, in order to achieve optimal CoMP For operations such as preprocessing and selection of cooperative cells, the UE needs to feed back a large amount of channel-related information to the base station; in addition, because PMI, CQI and other information compress the downlink channel information to a certain extent, they cannot completely and accurately reflect the downlink channel information. This will have a certain impact on operations such as downlink resource scheduling, precoding, and coordinated cell selection, resulting in downlink transmission quality degradation

[0005] For the acquisition method of uplink channel related information, since SRS usually occupies the last symbol of each subframe, the overhead is relatively large, and even if only one user among all users sends SRS, the last symbol in the subframe needs to be vacated. This will also cause a lot of waste of resources

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