D2D Transceiver Adaptive Transmission Feedback

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Solution Overview

Problem

Current device-to-device (D2D) communication in cellular networks experiences low spectral and energy efficiency due to non-adaptive transmission parameters in broadcast/multicast modes, leading to high bit error rates and poor quality of service, especially in scenarios with varying channel conditions.

Innovation Solution

Implementing a method where transceiver devices transmit reference signals and receive feedback messages containing channel characteristics, allowing the transmitter to adapt its transmission to specific devices based on estimated channel conditions, enabling efficient unicast, multicast, or broadcast modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If broadcast transmission is used in D2D communications, then coverage area is extended and multiple receivers can receive data simultaneously, but spectral efficiency and energy efficiency deteriorate due to non-adaptive transmission parameters

Engineering Contradiction:
Improvecoverage areaVSAvoidenergy efficiency
Core Design Contradiction:
Area of stationary objectVSUse of energy by moving object

Solution Approach 1:

The invention segments the broadcast transmission by dividing receivers into different groups based on their channel conditions. Each group receives transmissions adapted to its specific channel characteristics, allowing the system to maintain broad coverage while improving energy efficiency by avoiding excessive power consumption for receivers with good channel conditions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces dynamic adaptation of transmission parameters based on feedback from receivers about their channel conditions. The transmitter adjusts modulation and coding schemes dynamically according to the received feedback, enabling the system to optimize energy consumption while maintaining coverage for all receivers.

Inventive Principle:
Principle #15Dynamics

2Productivity

If broadcast transmission is used in D2D communications, then multiple receivers can be served simultaneously, but bit error rate increases and quality of service deteriorates due to lack of channel condition adaptation

Engineering Contradiction:
Improvenumber of receivers servedVSAvoidbit error rate
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The invention implements a feedback mechanism where receivers report their channel conditions (such as reference signal received power) back to the transmitter. Based on this feedback, the transmitter adapts its transmission parameters to ensure reliable delivery to all receivers, thereby reducing bit error rate while maintaining the ability to serve multiple receivers simultaneously.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The invention applies different transmission qualities to different receivers based on their local channel conditions. Receivers with poor channel conditions receive transmissions with more robust modulation and coding, while receivers with good channel conditions receive transmissions with higher data rates, ensuring overall system reliability while maintaining high productivity.

Inventive Principle:
Principle #3Local quality

3Use of energy by moving object

If adaptive transmission based on channel feedback is implemented, then spectral efficiency and energy efficiency improve, but device complexity increases due to feedback signaling requirements

Engineering Contradiction:
Improveenergy efficiencyVSAvoiddevice complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The invention extracts only the essential feedback information needed for adaptation (such as reference signal received power measurements) and transmits this condensed feedback to the transmitter. This approach reduces the feedback signaling overhead and device complexity while still enabling effective adaptive transmission for improved energy efficiency.

Inventive Principle:
Principle #2Taking out (Extraction)

4Measurement precision

If channel characteristics feedback is collected from multiple receivers, then transmission adaptation accuracy improves, but signaling overhead and processing complexity increase

Engineering Contradiction:
Improvechannel estimation accuracyVSAvoidsignaling overhead
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The invention merges the feedback information from multiple receivers and uses it collectively to determine adaptation parameters for different receiver groups. By combining feedback data and applying group-based adaptation rather than individual receiver adaptation, the system achieves good channel estimation accuracy while reducing signaling overhead and processing complexity.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3590301B1D2d communications in a cellular network
Publication Date: 2021.07.21 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3590301B1 patent drawingFigure 1
  • EP3590301B1 patent drawingFigure 2
  • EP3590301B1 patent drawingFigure 3

AI summary

A method performed by a first transceiver device (10) in D2D communication with second transceiver devices (20) in a cellular network comprises transmitting (S10) a reference signal comprising an identity of the first transceiver device, and receiving (S20) feedback messages from the second transceiver devices, where a feedback message comprises the identity of the first and an identity of the second transceiver device, and channel characteristics of a radio channel between the first and the second transceiver device, where the channel characteristics are estimated by the second transceiver device. The method further comprises deciding (S30), based on the feedback messages, whether a second transceiver device should be included in a set of intended devices to which the first transceiver device will perform a transmission of a communication signal. The method also comprises performing (S40) a transmission of the communication signal to the set of intended devices, where the transmission is adapted to the set of intended devices based on the feedback messages received from the intended devices.