Orthogonal Sequence Allocation for Uplink Interference Control

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Solution Overview

Problem

Existing telecommunication systems face interference issues due to imperfections in hardware and communication channels, which affect the orthogonal properties of sequences used for shared channel transmission, leading to manageable interference beyond design limits.

Innovation Solution

A method and control circuit for allocating orthogonal sequences to user equipment devices by determining the UE with the largest transmission resource and reserving sequences with quadrature phase offsets to minimize interference, ensuring optimal performance by prioritizing sequence allocation based on transmission resources and adapting to changing conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If orthogonal sequences are allocated to multiple UEs sharing a channel, then channel utilization is improved, but interference between sequences increases due to hardware and channel imperfections

Engineering Contradiction:

Improvechannel utilizationVSAvoidinterference between sequences

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by pre-identifying and reserving the quadrature phase offset sequence corresponding to the UE with the largest transmission resource before allocating sequences to other UEs. This proactive reservation prevents future interference issues rather than reacting to them after allocation. The method determines which UE has the largest transmission resource (power or resource blocks), identifies its orthogonal sequence, finds the quadrature phase offset sequence, and reserves it before proceeding with allocation to remaining UEs.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent converts the potentially harmful quadrature phase offset relationship into a beneficial reservation mechanism. Instead of treating quadrature phase offset sequences as random interferers, the invention systematically identifies and reserves these specific sequences in advance for the UE with the largest transmission resource, transforming what could be a source of interference into a protected allocation strategy that actually improves overall system performance.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Ease of operation

If sequences are allocated without considering transmission resource magnitude, then allocation simplicity is maintained, but overall group performance deteriorates

Engineering Contradiction:

Improveallocation simplicityVSAvoidgroup performance

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent applies local quality by treating UEs differently based on their transmission resource allocation. Rather than applying a uniform allocation rule to all UEs, the method identifies the specific UE with the largest transmission resource (local characteristic) and applies special sequence reservation treatment to that UE's quadrature phase offset sequence. This differentiated approach optimizes performance for the most resource-intensive UE while maintaining standard allocation for others, improving overall group performance without significantly complicating the allocation process.

Inventive Principle:

Principle #3Local quality

3Device complexity

If fixed sequence allocation is used, then system complexity is reduced, but adaptability to changing transmission circumstances deteriorates

Engineering Contradiction:

Improvesystem complexityVSAvoidadaptation to transmission circumstances

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamics by making the sequence allocation adaptive to changing transmission conditions. The system periodically re-evaluates which UE has the largest transmission resource (power or resource blocks) and dynamically adjusts sequence reservations accordingly. This allows the allocation scheme to adapt to varying channel conditions, traffic patterns, and resource requirements without requiring complete re-allocation, balancing system complexity with adaptability through selective re-evaluation rather than continuous dynamic adjustment.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS8935403B2Control circuit and method for allocating orthogonal sequences

Publication Date: 2015.01.13 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

A method for allocating orthogonal sequences to user equipment devices, UEs, of a group sharing a channel of a telecommunication system is disclosed. The method comprises determining which UE of the group having largest transmission resource assigned for a physical uplink shared channel, PUSCH; determining a first orthogonal sequence of the UE of the group having largest transmission resource assigned; determining a second sequence that equals a quadrature phase offset of the first orthogonal sequence; reserving said second sequence when allocating sequences to remaining UEs of the group by avoiding the second sequence as long as there are other orthogonal sequences available. A control circuitry for a network node is also disclosed.