Cyclic Shift Division for Wireless Control Information Transmission
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Solution Overview
Problem
Wireless communication systems face performance deterioration due to errors in transmitting uplink control information, necessitating a method to enhance the reliability and reduce interference during control information transmission.
Innovation Solution
A method involving the generation of a cyclically shifted sequence by shifting a base sequence, dividing available cyclic shifts into parts based on control information type, and separating them with unallocated shifts to reduce interference and improve transmission reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple pieces of control information are transmitted using cyclically shifted sequences, then the transmission capacity is improved, but mutual interference between different control information increases
Solution Approach 1:
The available cyclic shifts of the base sequence are divided into multiple parts (first part, second part, etc.) according to the type of control information. Each part is allocated to a specific type of control information (e.g., first part for ACK/NACK, second part for CQI). This segmentation prevents different types of control information from interfering with each other while maintaining high transmission capacity through cyclic shifts within each part.
Solution Approach 2:
At least one unallocated cyclic shift is inserted between different parts of control information as a buffer zone. This unallocated cyclic shift acts as an intermediary that provides additional separation between different types of control information, further reducing mutual interference while allowing the system to maintain high transmission capacity through the available cyclic shifts within each part.
2Productivity
If cyclic shifts are allocated densely to maximize transmission capacity, then productivity is improved, but interference between control information increases
Solution Approach 1:
The cyclic shifts are segmented into multiple parts with clear boundaries, where each part is dedicated to a specific type of control information. This segmentation ensures that even with dense allocation within parts, the overall system maintains reliability by preventing cross-type interference through the unallocated cyclic shifts that serve as protective boundaries between parts.
3Reliability
If cyclic shifts are separated by unallocated shifts to reduce interference, then reliability is improved, but transmission capacity decreases
Solution Approach 1:
The cyclic shifts are segmented into multiple parts with unallocated cyclic shifts as boundaries. This segmentation provides reliability by reducing interference between different control information types, while maintaining transmission capacity by allowing dense allocation of cyclic shifts within each segmented part. The unallocated cyclic shifts act as minimal necessary separators that preserve reliability without excessively reducing capacity.
Solution Approach 2:
Different regions of the cyclic shift space are assigned different qualities/functions: within each part, cyclic shifts are densely allocated for high capacity, while between parts, unallocated cyclic shifts provide separation for high reliability. This local differentiation optimizes both capacity and reliability in their respective regions without compromising the overall system.
Data Source
AI summary
A method of transmitting control information includes generating a cyclically shifted sequence by cyclically shifting a base sequence by a cyclic shift amount, generating a modulated sequence based on a modulation symbol for control information and the cyclically shifted sequence, and transmitting the modulated sequence on a plurality of subcarriers, wherein available cyclic shifts of the base sequence are divided into a first part and a second part according to a type of the control information, and the first part and the second part are separated by at least one unallocated cyclic shift of the base sequence.