Dynamic OFDM Symbol Allocation for PDCCH Control Channels
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
OFDM systems have a limited number of frequencies designated for control information, which can lead to unnecessary limitations in data transmission, as the amount of control information can vary between sub-frames, and existing technologies do not efficiently utilize this constraint to enhance data transmission reliability and efficiency.
Innovation Solution
A base station transmitter and user equipment receiver system that dynamically allocates OFDM symbols for the physical downlink control channel by representing control information as two bits, forming a codeword with repetitions, and equally spacing these groups across the bandwidth for transmission, allowing for flexible allocation of OFDM symbols based on received control information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed number of tones are designated for transmitting control information, then reliable control information transmission is achieved, but data transmission rate is limited
Solution Approach 1:
The patent applies dynamics by making the number of OFDM symbols allocated to PDCCH variable rather than fixed. The base station dynamically adjusts the PDCCH symbol count based on actual control information requirements, allowing the system to adapt between reliability-focused configurations (more symbols for control) and throughput-focused configurations (fewer symbols for control, more for data)
2Reliability
If control information is transmitted with high reliability guarantees, then fast and reliable receipt is achieved, but transmission overhead increases
Solution Approach 1:
The patent changes the parameter of PDCCH resource allocation from a static fixed value to a dynamic variable that adapts to actual needs. By adjusting the number of OFDM symbols allocated to PDCCH based on control information volume, the system achieves reliable transmission only when necessary, reducing overhead when control information is minimal
Data Source
AI summary
A base station transmitter for use with an orthogonal frequency division multiplexing (OFDM) communications system, a method of dynamically allocating OFDM symbols needed for a physical downlink control channel (PDCCH) in a downlink sub-frame from a base station and a user equipment (UE) receiver for use with the OFDM communications system. In one embodiment, the UE receiver includes: (1) a receive unit configured to receive a downlink signal, the signal having groups of control information and (2) a processing unit configured to extract from the groups of control information a number of OFDM symbols needed for PDCCH in a sub-frame of the downlink signal.