DCI Format 1A Merging for LTE Control Channel Overhead Reduction
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Solution Overview
Problem
In LTE systems, closed loop MIMO transmission leads to increased PDCCH overhead and congestion, reducing the utilization rate of control channel resources, especially for UEs at the cell edge or in high-speed motion.
Innovation Solution
The method involves configuring data channel transmission modes that correspond to multiple transmission manners, using DCI formats with identifier information to indicate between closed loop MIMO and transmit diversity or open loop single-antenna-port transmission, thereby reducing control channel overhead and improving scheduling efficiency and flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If closed loop MIMO transmission is used with DCI format 2C, then transmission performance is improved, but PDCCH overhead increases and control channel congestion occurs
Solution Approach 1:
The patent combines multiple transmission modes (closed loop MIMO and transmit diversity/open loop single-antenna-port) into a single DCI format 1A structure. By merging the functionality of multiple DCI formats into one unified format with mode indication bits, the patent reduces control channel overhead while maintaining support for multiple transmission modes, directly resolving the contradiction between transmission performance and PDCCH overhead.
Solution Approach 2:
The patent makes DCI format 1A universal by enabling it to indicate multiple transmission modes through mode indication bits. This single DCI format can now serve multiple functions: indicating closed loop MIMO transmission, transmit diversity transmission, or open loop single-antenna-port transmission, thereby reducing the need for multiple specialized DCI formats and reducing overall control channel overhead.
2Adaptability or versatility
If DCI format 2C is used for closed loop MIMO, then scheduling capability is improved, but control channel resource utilization decreases
Solution Approach 1:
The patent merges the scheduling capabilities of multiple DCI formats into a unified DCI format 1A structure. By combining the scheduling functions for closed loop MIMO, transmit diversity, and open loop single-antenna-port transmissions into one format with mode indication bits, the patent maintains comprehensive scheduling capability while improving control channel resource utilization through reduced overhead.
Solution Approach 2:
The patent changes the parameter structure of DCI format 1A by adding mode indication bits that enable the same DCI format to support multiple transmission modes. This parameter change allows DCI format 1A to achieve the scheduling capability previously requiring multiple specialized formats, thereby improving control channel resource utilization without sacrificing versatility.
3Adaptability or versatility
If multiple DCI formats are used for different transmission modes, then transmission flexibility is improved, but control channel complexity increases
Solution Approach 1:
The patent merges multiple transmission mode indications into a single DCI format 1A structure by incorporating mode indication bits. This consolidation reduces control channel complexity by eliminating the need for multiple separate DCI formats while maintaining transmission flexibility, as the same DCI format can now indicate different transmission modes through its embedded mode indication bits.
Solution Approach 2:
The patent makes DCI format 1A a universal format that can indicate multiple transmission modes (closed loop MIMO, transmit diversity, open loop single-antenna-port) through mode indication bits. This universality simplifies the control channel structure by replacing multiple specialized formats with one multi-functional format, thereby reducing control channel complexity while preserving transmission flexibility.
Data Source
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AI summary
The present invention discloses a control information transmission method, a user equipment, and a base station. The method includes: obtaining a data channel transmission mode configured by a base station; determining a downlink control information DCI format set corresponding to the transmission mode, where the DCI format set includes a first DCI format, and the first DCI format includes single-codeword control information; and detecting, according to the DCI format set, control signaling sent by the base station and corresponding to the DCI format set. The user equipment includes a first obtaining module, a first determining module, and a detecting module. The base station includes a configuring module, a first determining module, and a first sending module. Because the data channel transmission mode corresponds to at least two transmission manners, the control information transmission method, the user equipment, and the base station in embodiments of the present invention can enhance a control channel, reduce overhead of the control channel, improve system scheduling efficiency and flexibility, overcome the congestion problem of the control channel, and improve the utilization rate of control channel resources of a system.