Dynamic Reference Signal Transmission for LTE-A Throughput
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
LTE-A systems face challenges in improving system throughput while maintaining backward compatibility with LTE systems and supporting legacy LTE receivers without degrading reception performance.
Innovation Solution
The method involves determining whether a dedicated reference signal or a common reference signal is detected in a subframe to estimate and process data channels, with the transmitter deciding whether to transmit a dedicated or common reference signal based on higher layer signaling, and multiplexing these signals with data signals for efficient transmission and reception.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If dedicated reference signals are transmitted in all subframes, then data reception performance is improved, but system overhead and complexity increase
Solution Approach 1:
The patent implements dynamic reference signal transmission by determining whether to transmit dedicated reference signals on a per-subframe basis rather than continuously. The transmitter uses higher layer signaling to indicate the presence or absence of dedicated reference signals in each subframe, allowing the system to adapt reference signal transmission to actual channel conditions and traffic requirements, thereby reducing overall system overhead while maintaining reception performance where needed
Solution Approach 2:
The system changes the transmission parameter of reference signals by switching between two modes: transmitting dedicated reference signals in some subframes and using only common reference signals in other subframes. This parameter change allows flexible control of reference signal density and type, optimizing the balance between reception performance and system overhead
2Productivity
If common reference signals are used for all receivers, then system overhead is reduced, but data rate and reception performance for specific receivers deteriorate
Solution Approach 1:
The patent applies local quality by providing different reference signal types to different receivers or different subframes based on specific needs. Dedicated reference signals are transmitted to specific receivers experiencing poor channel conditions or requiring higher data rates, while common reference signals serve receivers with adequate channel conditions. This localized optimization improves overall system throughput by allocating reference signal resources efficiently rather than uniformly
3Measurement precision
If dedicated reference signals are transmitted frequently, then channel estimation accuracy is improved, but signal overhead and resource consumption increase
Solution Approach 1:
The system implements partial action by transmitting dedicated reference signals only in certain subframes rather than in every subframe. The transmitter determines on a per-subframe basis whether dedicated reference signals are necessary based on channel conditions, receiver requirements, and traffic patterns. This partial transmission reduces overall signal overhead while maintaining sufficient channel estimation accuracy for data reception in the subframes where dedicated reference signals are present
Data Source
AI summary
A method and apparatus for transmitting/receiving reference signals in Long Term Evolution (LTE) and LTE-Advanced (LTE-A) systems includes determining whether a dedicated reference signal is detected in a current subframe; estimating, if a dedicated reference signal is detected in the current subframe, a data channel using the dedicated reference signal to receive data; and estimating, if no dedicated reference signal is detected in the current subframe, a data channel using a common reference signal detected in the current subframe to receive data. The transmission scheme uses a DeModulation Reference Signal (DM-RS) for channel response estimation. To secure backward compatibility of the LTE-A system, a Common Reference Signal is transmitted in normal subframes.