Toeplitz Matrix Channel Hopping for Asynchronous Rendezvous

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Solution Overview

Problem

Current methods for establishing communication links between user equipment (UEs) in radio communication cells using dynamic spectrum access (DSA) technologies face challenges in achieving efficient and asynchronous rendezvous with low computational intensity, particularly in scenarios without a central control channel, where existing algorithms like GOS and MC algorithms have limitations in time-to-rendezvous (TTR) and complexity.

Innovation Solution

The use of a user equipment (UE) configured with a tuner to tune a communication unit to a channel sequence vector partially vectorized from a symmetric Toeplitz matrix, ensuring an order of channels for rendezvous, which is less computationally intensive and provides a guaranteed rendezvous with low and tightly bounded TTR, even in asynchronous symmetric channel-hopping systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If symmetric hopping-based rendezvous techniques are used, then rendezvous is ensured for a particular number of cases, but the maximum time-to-rendezvous (TTR) is limited and the system requires time synchronization which demands additional infrastructure

Engineering Contradiction:
Improverendezvous guaranteeVSAvoidtime-to-rendezvous (TTR)
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent changes the mathematical parameters of the hopping sequence generation by using a Toeplitz matrix structure with specific symmetry properties. This allows asynchronous UEs to generate coordinated hopping sequences without requiring time synchronization, thereby reducing TTR while maintaining rendezvous guarantee in unaided systems.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces asymmetric elements in the Toeplitz matrix construction where the first row serves as the generating vector, creating a structured asymmetry that enables asynchronous operation. This asymmetric structure allows UEs to independently generate sequences that will inevitably intersect without requiring symmetric synchronization.

Inventive Principle:
Principle #4Asymmetry

2Ease of operation

If a central controller or common central control channel is used for aided rendezvous, then the rendezvous process is simplified, but the system becomes vulnerable to jamming and overload attacks due to low flexibility and scalability

Engineering Contradiction:
Improverendezvous process simplificationVSAvoidvulnerability to jamming and overload attacks
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent enables UEs to self-generate their channel hopping sequences using the Toeplitz matrix method without relying on a central controller. Each UE independently computes its sequence based on local initialization vectors, making the system decentralized and resistant to jamming and overload attacks while maintaining operational simplicity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The Toeplitz matrix structure serves as a mathematical intermediary that coordinates asynchronous UEs without requiring a physical central controller. The matrix structure inherently provides the coordination function that would otherwise require centralized control, eliminating the vulnerability to attacks on central infrastructure.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If unaided distributed channel search is used, then flexibility and scalability are improved, but the computational complexity increases and rendezvous efficiency decreases

Engineering Contradiction:
Improveflexibility and scalabilityVSAvoidcomputational complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the channel search process into structured hops based on Toeplitz matrix rows and columns. Instead of exhaustive random search, UEs systematically segment their search through predetermined hopping patterns, reducing computational complexity while maintaining the distributed flexibility of unaided systems.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The Toeplitz matrix structure provides preliminary organization of the channel search space before UEs begin hopping. By pre-defining the mathematical structure that guarantees intersection, the system reduces the computational burden during actual rendezvous execution while maintaining distributed operation.

Inventive Principle:
Principle #10Preliminary action

4Reliability

If existing algorithms like GOS or MC are used, then rendezvous can be achieved, but the time-to-rendezvous is not tightly bounded and computational intensity is high

Engineering Contradiction:
Improverendezvous achievementVSAvoidtime-to-rendezvous bounding
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent changes the mathematical parameters from general hopping sequences to specific Toeplitz matrix-based sequences with proven intersection properties. This parameter change provides analytically bounded TTR while reducing computational intensity through the efficient structure of Toeplitz matrices that can be generated with O(N) complexity.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS9847857B2Establishing a communication link between user equipments
Publication Date: 2017.12.19 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • US9847857B2 patent drawing
  • US9847857B2 patent drawing
  • US9847857B2 patent drawing

AI summary

Methods and apparatus for establishing a communication link between a first user equipment and at least one other user equipment in a radio communication cell using a radio frequency spectrum divided into a plurality of channels. The first user equipment comprises a tuner configured to tune a communication unit to channels of a channel sequence vector in order. The channel sequence vector comprises at least a partial vectorization of a symmetric Toeplitz matrix formed from a set of the plurality of channels. The communication unit is configured, at each channel, to receive link data for establishing a communication link with the at least one other user equipment. A link establisher is configured to establish a communication link with the at least one other user equipment over the tuned channel if the link data is received.