SRS Transmission Comb 8 Orthogonality via Cyclic Shift Rules

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Solution Overview

Problem

Current SRS transmission in NR networks faces challenges with transmission comb 8, particularly in maintaining orthogonality between SRS ports, which affects SRS capacity and measurement performance.

Innovation Solution

The introduction of a rule for determining allowed cyclic shifts and an updated formula for port-specific cyclic shifts ensures orthogonality, allowing for more than 6 cyclic shifts with transmission comb 8, enhancing SRS capacity and configuration for multi-port SRS resources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If transmission comb 8 is used for SRS transmission, then frequency resource efficiency is improved, but maintaining orthogonality between SRS ports becomes difficult

Engineering Contradiction:

Improvefrequency resource efficiencyVSAvoidorthogonality between SRS ports

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent changes the cyclic shift parameter values to specific subsets (e.g., {0, 3, 6} or {1, 4, 7}) that are multiples of 3, which maintains orthogonality when using transmission comb 8. This parameter adjustment ensures that SRS sequences from different ports remain orthogonal despite the dense frequency spacing of comb 8.

Inventive Principle:

Principle #35Parameter changes

2Quantity of substance

If more cyclic shifts are used with transmission comb 8, then SRS capacity is improved, but sequence orthogonality deteriorates

Engineering Contradiction:

ImproveSRS capacityVSAvoidsequence orthogonality

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent defines specific parameter constraints where the cyclic shift value must be a multiple of 3 (i.e., cyclicShift % 3 = 0). This parameter restriction enables up to 6 orthogonal cyclic shifts (0, 3, 6, 9, 12, 15) to be used with transmission comb 8, thereby increasing SRS capacity while maintaining sequence orthogonality.

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If cyclic shift values are increased to support more ports, then multi-port SRS is improved, but measurement precision deteriorates

Engineering Contradiction:

Improvemulti-port SRS supportVSAvoidchannel estimation precision

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent selects cyclic shift values that are multiples of 3 (0, 3, 6, 9, 12, 15) to ensure that the phase rotation between different ports maintains a consistent pattern that preserves orthogonality. This parameter selection ensures that channel estimation precision is maintained while supporting up to 6 ports with transmission comb 8.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20240187188A1Sounding reference signal transmission comb eight

Publication Date: 2024.06.06 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

According to some embodiments, a method performed by a wireless device comprises obtaining an SRS configuration for an SRS resource having a base SRS sequence. The SRS configuration comprises a number of SRS ports in the SRS resource, a transmission comb of value 8, and an indication of a set of cyclic shifts for use with the SRS resource. The indicated set of cyclic shifts is a subset of a set of cyclic shifts of the base SRS sequence. Each cyclic shift in the subset of cyclic shifts results in an SRS sequence orthogonal to the base SRS sequence. The method further comprises transmitting an SRS using transmission comb 8 and the indicated set of cyclic shifts.