Method and apparatus for providing downlink control information in a MIMO wireless communication system
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Solution Overview
Problem
Conventional 3GPP LTE systems face challenges in accurately receiving downlink signals due to control information limitations in new MIMO transmission methods, particularly with dual-layer beamforming and UE-specific reference signals, which restrict the transmission of rank 8 and multi-user MIMO scenarios.
Innovation Solution
A method and apparatus for transmitting and receiving downlink control information in a wireless communication system that supports MIMO transmission by including information indicating the number of layers, enabling codewords, and UE-specific reference signals, allowing for accurate demodulation of downlink data using UE-specific reference signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If conventional DCI formats are used in new MIMO transmission methods, then device complexity is reduced, but downlink signal reception accuracy deteriorates
Solution Approach 1:
The DCI format is segmented into distinct fields: a first field indicating the number of layers (N), a second field indicating the number of enabled codewords (1 or 2), and a third field containing downlink resource allocation information. This segmentation allows each field to carry specific control information necessary for new MIMO transmission methods, ensuring accurate downlink signal reception while maintaining structured complexity.
2Productivity
If new MIMO schemes are introduced to increase system capacity, then productivity is improved, but control information completeness deteriorates
Solution Approach 1:
The DCI format is designed in advance to include all necessary control information fields required for new MIMO schemes such as dual-layer beamforming and UE-specific reference signal based multi-user MIMO. By preliminarily incorporating fields for indicating the number of layers (N up to 8), number of codewords, and resource allocation, the patent ensures complete control information is available before transmission, enabling accurate demodulation and supporting enhanced system capacity.
Data Source
AI summary
The present invention relates to a method in which a user equipment receives a downlink signal from a base station in a wireless communication system that supports downlink mimo transmission according to one embodiment of the present invention comprises: receiving downlink control information that includes information indicative of the number of layers (n, 1≤n≤8) where one or two enabled code words of the downlink mimo transmission are mapped; on the basis of the downlink control information, receiving downlink data transmitted over the respective n layers and a ue-specific reference signal for each of the n layers; and decoding the downlink data on the basis of the ue-specific reference signals, wherein the information indicative of the number of layers can further include information on a code for identifying the ue-specific reference signals.