Generalized Chu Sequence Signaling for Wireless Detection

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Solution Overview

Problem

Current wireless communication systems, such as LTE, face challenges in accurately distinguishing between downlink transmissions from serving and non-serving eNBs due to the use of gold sequences, leading to higher probabilities of false alarms and missed detections, especially in unlicensed frequency spectra where multiple devices contend for the same band.

Innovation Solution

Implementing generalized Chu sequences, which are scrambled using a common pseudorandom sequence, allows eNBs to indicate the start of downlink transmissions, enabling UE to differentiate between serving and non-serving eNBs by using their respective sequences, thereby reducing false alarms and improving detection accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If gold sequences are used for downlink transmission signaling, then the system can support multiple users, but the probability of false alarms and missed detections increases

Engineering Contradiction:

Improvenumber of users supportedVSAvoiddetection accuracy

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent changes the fundamental parameter of the sequence type from gold sequences to generalized Chu sequences. This parameter change provides better autocorrelation and cross-correlation properties, which directly reduces false alarms and missed detections while maintaining support for multiple users through the flexible root index mechanism.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent substitutes the mathematical structure of gold sequences with that of generalized Chu sequences. This substitution replaces the underlying mathematical mechanism with one that inherently provides superior correlation properties, thereby improving detection reliability without sacrificing multi-user support capability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of manufacture

If gold sequences are used for transmission signaling, then implementation is straightforward, but false alarms increase in unlicensed frequency spectra

Engineering Contradiction:

Improveimplementation simplicityVSAvoidfalse alarms

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent changes the sequence type parameter from gold sequences to generalized Chu sequences, which have superior autocorrelation and cross-correlation properties. This parameter change reduces false alarms in unlicensed spectra while maintaining implementation feasibility through standardized generation methods using root indices and scrambling sequences.

Inventive Principle:

Principle #35Parameter changes

3Measurement precision

If generalized Chu sequences are used, then detection accuracy improves, but sequence generation complexity increases

Engineering Contradiction:

Improvedetection accuracyVSAvoidsequence generation complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent changes the sequence type to generalized Chu sequences, which provide superior detection accuracy through better correlation properties. The implementation complexity is managed by parameterizing the sequence generation through root indices and scrambling sequences, which can be efficiently computed using established mathematical methods.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent introduces root indices as intermediary parameters that simplify the generation of generalized Chu sequences. These root indices act as compact representations that enable efficient sequence generation and differentiation between serving and non-serving eNBs without requiring complex generation algorithms.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Reliability

If scrambled sequences are used to differentiate eNBs, then false alarms reduce, but processing requirements increase

Engineering Contradiction:

Improvefalse alarm reductionVSAvoidprocessing power

Core Design Contradiction:

ReliabilityVSPower

Solution Approach 1:

The patent changes the sequence structure to include scrambling based on root indices and pseudorandom sequences. This parameter change reduces false alarms by providing unique signatures for different eNBs while managing processing requirements through efficient correlation-based detection algorithms that leverage the mathematical properties of Chu sequences.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11664919B2Method and apparatus for signaling using generalized Chu sequences

Publication Date: 2023.05.30 QUALCOMM INC

AI summary

A base station may determine a root for a sequence to be included in a signal to a UE. The base station may generate a generalized Chu sequence based on the root and scramble the generalized Chu sequence using a pseudorandom sequence that is common to a plurality of base stations. The base station may transmit the scrambled generalized Chu sequence to indicate the beginning of a downlink transmission. The UE may receive this scrambled generalized Chu sequence and determine if a beginning of a downlink transmission from a serving base station based on the received generalized Chu sequence and an expected generalized Chu sequence.