LTE Uplink Interleaver Mapping for Multi-Layer Control Multiplexing
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Solution Overview
Problem
Current multi-antenna wireless communication systems face challenges in efficiently multiplexing data and control information, particularly in channel interleaving, which affects the performance of uplink transmissions in mobile communication systems like LTE.
Innovation Solution
A method and apparatus for channel interleaving in a multi-antenna wireless communication system, where channel quality indicator (CQI) information and coded data are configured as vectors, and coded rank indicator (RI) and acknowledgement (ACK)/negative ACK (NACK) information are repeated and scrambled, then mapped to an interleaver matrix, generating an output vector sequence by reading the matrix column by column, with each entry defined by a product of modulation order and the number of transmission layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If data and control information are multiplexed using conventional methods, then transmission can be performed, but transmission efficiency is reduced and cubic metric increases
Solution Approach 1:
The transmission data is segmented into multiple code blocks, and channel interleaving is applied independently to each code block. This segmentation allows for more flexible resource allocation and reduces the cubic metric by distributing control information across multiple segments rather than concentrating it, thereby improving uplink transmission efficiency
Solution Approach 2:
The patent introduces a new dimension in resource allocation by mapping control information to specific resource elements in the time-frequency grid based on their importance and channel conditions. This dimensional approach to resource allocation optimizes the multiplexing of data and control information, reducing interference and improving transmission efficiency while managing cubic metric
2Reliability
If channel interleaving is performed without considering control information, then data transmission is simplified, but control information reliability deteriorates
Solution Approach 1:
Different interleaving strategies are applied to different portions of the transmission based on local requirements. Control information is allocated to resource elements with better channel conditions and protected with appropriate redundancy, while data uses standard interleaving. This localized optimization ensures control information reliability without unnecessarily increasing overall system complexity
Solution Approach 2:
The patent dynamically adjusts interleaving parameters such as interleaver size, shift amount, and resource element allocation based on channel conditions and traffic type. This parameter adaptation allows the system to optimize control information protection under varying conditions while maintaining manageable complexity through standardized algorithms
3Productivity
If multiple transmission layers are used, then data rate is improved, but multiplexing of control information becomes more difficult
Solution Approach 1:
The channel interleaving mechanism is designed to handle multiple transmission layers universally by applying the same interleaving algorithm across all layers with layer-specific parameters. Control information is multiplexed across layers using a standardized mapping rule that identifies the appropriate layer based on resource element indices, enabling multi-layer operation without proportionally increasing multiplexing complexity
Data Source
AI summary
A method of transmitting a signal to a base station at a user equipment (UE) in a multi-antenna wireless communication system, can include generating interleaver input vector sequences, wherein the interleaver input vector sequences comprise vectors having a predetermined bit size, mapping the interleaver input vector sequences to an interleaver matrix, generating an output bit sequence by reading the interleaver matrix column by column, and transmitting the output bit sequence to the base station, wherein the predetermined bit size is defined by a product of a modulation order Qpm and the number NL of transmission layers.