Aperiodic SRS Carrier Segmentation for LTE Uplink Capacity

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Solution Overview

Problem

In LTE wireless communication systems, the increasing number of User Equipment (UEs) leads to saturation of channel measurement resource regions, reducing uplink capacity and limiting the transmission rate, as existing methods either reduce data channel capacity or interrupt conventional channel sounding reference signal transmission.

Innovation Solution

The method involves using two carriers for data and channel measurement, with the same transmission power, and employing unitary precoding for channel sounding reference signals, allowing simultaneous transmission without reducing data channel capacity and maintaining orthogonality between UEs, while dynamically controlling SRS bandwidth and scheduling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If channel sounding reference signal regions are increased to support more UEs, then the number of UEs that can be measured increases, but uplink capacity is reduced

Engineering Contradiction:
Improvenumber of UEsVSAvoiduplink capacity
Core Design Contradiction:
Quantity of substanceVSProductivity

Solution Approach 1:

The patent divides the reference signal transmission into two separate carriers: one carrier dedicated for data transmission and another carrier for channel sounding reference signal transmission. This segmentation allows simultaneous operation of data channels and reference signals without resource conflicts, enabling support for more UEs while maintaining uplink capacity on the data carrier.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If reference signal bandwidth is increased to improve measurement resolution, then channel measurement accuracy improves, but available bandwidth for multiplexing is reduced

Engineering Contradiction:
Improvechannel measurement resolutionVSAvoidmultiplexing capacity
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent moves the channel sounding reference signal transmission to a different frequency dimension by using a separate carrier. This allows the reference signal to occupy a dedicated bandwidth on the second carrier without competing with data channels on the first carrier, achieving high measurement resolution while preserving multiplexing capacity across the system.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If data transmission is interrupted to transmit channel sounding reference signals, then channel measurement can be performed, but data channel capacity is reduced

Engineering Contradiction:
Improvechannel measurementVSAvoiddata channel capacity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent segments the transmission resources by allocating different carriers for data and reference signals. This allows simultaneous transmission of both data channels and channel sounding reference signals without interruption, maintaining full data channel capacity while enabling reliable channel measurement through the dedicated reference signal carrier.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2765732B1Efficient transmion of reference signals in wireless communication systems
Publication Date: 2019.09.04 NOKIA TECHNOLOGIES OY
  • EP2765732B1 patent drawingFigure 1
  • EP2765732B1 patent drawingFigure 2
  • EP2765732B1 patent drawingFigure 3

AI summary

Methods and apparatuses for generating a channel sounding reference signal in a wireless communication system are discussed. In one aspect, a method is provided for User Equipment (UE) in a wireless communication system to transmit a channel Sounding Reference Signal (SRS). The method includes receiving a control channel for uplink data channel transmission from a Base Station (BS); determining whether the control channel includes information for aperiodic channel SRS transmission; and when it is determined that the control channel includes information for aperiodic channel SRS transmission: transmitting uplink data through a first carrier; and transmitting the channel SRS through a second carrier; wherein the first carrier and the second carrier are transmitted simultaneously to the BS.