Continuous CDM/FDM Structure for LTE Uplink Multiplexing
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Solution Overview
Problem
Current Long Term Evolution (LTE) wireless communication systems face challenges in efficiently multiplexing data on uplink channels, particularly for voice over Internet Protocol (VoIP) and bursty traffic, due to limitations in link budget and interference, which affect coverage and capacity, especially at the cell edge.
Innovation Solution
The implementation of a Continuous Code Division Multiplexing (CDM) and Frequency Division Multiplexing (FDM) structure for multiplexing data on uplink channels for at least four consecutive subframes, using techniques such as Zadoff-Chu sequences or pseudo-random noise sequences, to improve energy accumulation and reduce interference, allowing for efficient transmission of VoIP data and other small size bursty traffic.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional LTE uplink multiplexing is used, then system simplicity is maintained, but uplink coverage and capacity deteriorate due to link budget limitations and interference
Solution Approach 1:
The patent segments the uplink transmission by dividing it into continuous subframes (e.g., 4 consecutive subframes) and applying different multiplexing techniques (CDM within subframes, FDM between subframes) to different time-frequency resources. This segmentation allows the system to achieve continuous energy accumulation for improved coverage while managing interference through structured resource division, thereby resolving the contradiction between reliability improvement and complexity increase.
Solution Approach 2:
The patent employs a composite multiplexing structure that combines Code Division Multiplexing (CDM) and Frequency Division Multiplexing (FDM) in a hybrid approach. CDM is applied within continuous subframes to enable energy accumulation and improve link budget, while FDM is used between subframes to manage interference. This composite structure achieves both improved reliability and controlled complexity by leveraging the strengths of each multiplexing technique in appropriate contexts.
2Use of energy by moving object
If continuous transmission across subframes is implemented, then energy accumulation improves, but interference management becomes more difficult
Solution Approach 1:
The patent segments continuous transmission into structured units of consecutive subframes (e.g., 4 subframes) where CDM is applied within each segment. This segmentation enables energy accumulation within the continuous transmission window while the broader FDM structure between segments provides interference management. The segmentation allows the system to achieve continuous energy accumulation for improved link budget while maintaining controlled interference through structured resource division.
3Reliability
If CDM/FDM structure is applied for VoIP and bursty traffic, then link budget improves, but system complexity increases
Solution Approach 1:
The patent implements a dynamic CDM/FDM structure that adapts to different traffic types (VoIP and bursty traffic) by configuring continuous subframe bundles according to traffic characteristics. For VoIP traffic requiring continuous transmission, the system configures appropriate subframe bundling to maximize energy accumulation. The dynamic configuration allows the system to optimize link budget for different traffic patterns while managing complexity through standardized procedures and configurable parameters rather than fixed complex structures.
Data Source
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AI summary
A method, an apparatus, and a computer program product for wireless communication are provided in which information regarding use of a CDM and FDM structure for multiplexing data on a data channel for uplink for at least one subframe is determined. In addition, the data is multiplexed using the CDM/FDM structure for the at least one subframe based on the determined information.