GSM Block Format for Frequency Offset Estimation

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Solution Overview

Problem

Current wireless communication networks face performance degradation due to improper frequency offset estimation in extended coverage scenarios, leading to poor signal processing gain and backwards compatibility issues when introducing new features, which affects network resource allocation and device scheduling.

Innovation Solution

A new block format is introduced, where Uplink State Flag (USF) and Stealing Flag (SF) fields are interleaved and mapped over four bursts, with data and header fields interleaved over one burst but repeated across all four, allowing for effective frequency offset estimation while maintaining backwards compatibility with legacy devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If blind transmissions are used to support extended coverage, then radio coverage is improved, but frequency offset estimation becomes improper leading to poor signal processing gain

Engineering Contradiction:

Improveradio coverage areaVSAvoidfrequency offset estimation accuracy

Core Design Contradiction:

Area of stationary objectVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by pre-defining specific burst positions (e.g., first and third bursts) as reference bursts that contain known data patterns before transmission occurs. These reference bursts are prepared in advance to enable the receiving device to perform frequency offset estimation without requiring complex real-time processing of all transmitted bursts.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses copying by transmitting identical reference burst patterns at predetermined positions within the block structure. The receiving device can compare these copied reference patterns to estimate frequency offset, eliminating the need for complex estimation algorithms while maintaining accuracy in extended coverage scenarios.

Inventive Principle:

Principle #26Copying

2Reliability

If new features are introduced to improve coverage, then network performance is improved, but backwards compatibility with legacy devices deteriorates

Engineering Contradiction:

Improvenetwork performance reliabilityVSAvoidbackwards compatibility

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies universality by designing a block structure where reference bursts serve multiple functions: they enable frequency offset estimation for extended coverage scenarios while simultaneously maintaining compatibility with legacy devices that expect standard burst patterns. The reference bursts are positioned and structured such that both new and legacy devices can interpret them appropriately.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent applies local quality by introducing specialized reference bursts at specific positions within the block structure rather than modifying the entire block format. This allows the new frequency offset estimation feature to be implemented locally at reference burst positions while leaving other parts of the block structure unchanged for legacy device compatibility.

Inventive Principle:

Principle #3Local quality

3Measurement precision

If complex block structures are used to enable frequency offset estimation, then measurement precision is improved, but device complexity increases

Engineering Contradiction:

Improvefrequency offset estimation accuracyVSAvoidblock structure complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the block into distinct segments: reference bursts at predetermined positions containing known patterns, and data bursts carrying user data. This segmentation allows the frequency offset estimation function to be isolated to specific reference burst positions, simplifying the overall device complexity while maintaining estimation accuracy.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS10356795B2Transmitting device, receiving device, controlling node, and methods therein, for transmitting a block to the receiving device

Publication Date: 2019.07.16 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

Embodiments include methods performed by a receiving device configured for operation in a communications network. The methods include receiving, from a transmitting device in the network, four bursts comprising a block mapped according to a selected block format, wherein the block comprises a plurality of data and header bits. In some embodiments, the block further comprises Stealing Flag bits and Uplink State Flag bits. The methods also include determining whether the selected block format corresponds to a first block format in which the plurality of data and header bits are repeated in a corresponding plurality of same first positions in all four bursts. The methods also include demodulating the plurality data and header bits based on the determination of whether the selected block format corresponds to the first block format. Embodiments also include receiving devices comprising a receiver and a processor configured to perform operations corresponding to the exemplary methods.