Uplink Control Channel Joint Coding for Low CM Characteristic
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In LTE-A systems, there is a challenge in efficiently transmitting SR, ACK/NACK, or CQI information to the base station while maintaining a low Constant Modulus (CM) characteristic of uplink signals, especially when multiple Component Carriers (CCs) are involved, as existing methods do not effectively ensure simultaneous transmission of these information types with reduced uplink CM.
Innovation Solution
The method involves joint coding of SR and ACK/NACK information, or coding modulation of SR and CQI information, using physical resources of other non-SR channels within the same subframe, allowing for simultaneous transmission without requiring a dedicated SR channel, thereby maintaining low uplink CM.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If SR information is transmitted using a dedicated SR channel with OOK modulation, then the SR transmission is simple and direct, but the uplink CM characteristic deteriorates when SR is combined with ACK/NACK in the same subframe
Solution Approach 1:
The patent merges SR information with ACK/NACK information into a single uplink control message. The SR bit is concatenated with ACK/NACK bits to form a combined message that is jointly coded and modulated using QPSK, eliminating the need for separate SR channel transmission and maintaining low CM characteristic.
Solution Approach 2:
The uplink control channel is designed to handle multiple types of control information (SR, ACK/NACK, CQI) universally. The same physical resources and modulation scheme (QPSK) are used regardless of whether SR, ACK/NACK, or CQI is being transmitted, ensuring consistent CM characteristics across different control information types.
2Productivity
If multiple Component Carriers are configured in LTE-A system, then the system peak data rate is improved, but the complexity of managing SR, ACK/NACK, and CQI transmission across multiple CCs increases
Solution Approach 1:
The patent implements a universal uplink control channel that can carry SR, ACK/NACK, and CQI information from multiple Component Carriers simultaneously. By using joint coding and QPSK modulation for all control information types, the system maintains consistent transmission characteristics across multiple CCs without increasing management complexity.
Solution Approach 2:
The patent combines control information from multiple CCs into a single uplink transmission. SR bits from different CCs are concatenated with ACK/NACK bits, and the combined message is transmitted using shared physical resources, reducing the number of separate transmissions needed and simplifying multi-CC management.
3Ease of manufacture
If SR and ACK/NACK are transmitted separately on different channels, then each channel can be optimized independently, but the uplink signal CM characteristic deteriorates due to simultaneous transmission on the same CC
Solution Approach 1:
The patent merges SR and ACK/NACK into a single jointly coded message transmitted on the same physical channel using QPSK modulation. This eliminates the CM characteristic deterioration caused by simultaneous separate transmissions while maintaining the ability to independently optimize the joint coding and modulation parameters.
Data Source
Figure 1A~1B
Figure 2
Figure 3
AI summary
The present invention provides a method for transmitting an uplink Scheduling Request (SR), and the method includes, obtaing SR subframe configuration by receiving signaling, and transmitting SR information to an BS by using physical resources of other non SR channel for transmitting other uplink control information. By applying the present invention, the SR, acknowledgement/non-acknowledgement (ACK/NACK) or Channel Quality Indicator (CQI) information is returned to a Base Station (BS) when low Constant Modulus (CM) characteristic of an uplink Component Carrier (CC) is ensured.