Single Shift Register Sequence Generation for Low-Correlation Signals

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Solution Overview

Problem

Existing methods for generating multiple pseudorandom sequences face challenges in achieving low mutual correlation efficiently and with low resource consumption, leading to undesired spurs and spectral line issues in signal shaping applications.

Innovation Solution

A method using a single shift register structure to generate multiple sequences by reusing register elements and tapping at different positions, ensuring low mutual correlation and decorrelating sources of randomness for phase and cyclic shift randomization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If separate shift register structures are used for each sequence, then sequence generation capability is improved, but device complexity increases

Engineering Contradiction:
Improvesequence generation capabilityVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

A single shift register structure is designed to generate multiple pseudorandom sequences simultaneously by using different tap positions and feedback polynomial configurations. The same physical register elements are reused across different sequences, allowing one device to perform multiple sequence generation functions that would traditionally require separate registers for each sequence.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

Multiple sequence generation functions are merged into a single shift register structure. By combining the functionality of what would traditionally be separate registers into one unified structure with shared elements, the patent reduces overall device complexity while maintaining the capability to generate multiple sequences with low mutual correlation.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If multiple sequences are generated with low mutual correlation, then signal quality is improved, but resource consumption increases

Engineering Contradiction:
Improvesignal qualityVSAvoidresource consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The single shift register structure serves multiple sequence generation purposes simultaneously, reducing the total computational and hardware resources needed compared to using separate registers for each sequence. This universal structure maintains low mutual correlation between sequences while being more resource-efficient than traditional approaches.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent recovers and reuses the same physical register elements across different sequence generations. Instead of allocating dedicated resources for each sequence, the register elements are discarded from one sequence context and recovered/reused for another, maximizing resource utilization efficiency.

Inventive Principle:
Principle #34Discarding and recovering

3Device complexity

If register elements are reused for different sequences, then device complexity is reduced, but sequence correlation control becomes more difficult

Engineering Contradiction:
Improvedevice complexityVSAvoidsequence correlation control
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent controls sequence correlation by changing key parameters of the shift register configuration, specifically the tap positions and feedback polynomial coefficients. By carefully selecting different parameter sets for different sequences while using the same physical register, low mutual correlation is achieved despite element reuse. The parameter changes enable precise control over sequence properties without increasing hardware complexity.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3830686B1Method, transmitter and access point suitable for low-complexity implementation
Publication Date: 2025.09.03 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3830686B1 patent drawingFigure 1~3
  • EP3830686B1 patent drawingFigure 4~5
  • EP3830686B1 patent drawingFigure 6~7

AI summary

The invention relates in one example aspect to a structure for generating sequences, that comprises a binary shift register; a feedback structure connected to the shift register arranged to define a linear feedback shift register according to a polynomial; a first output arranged to collect one or more state values from a first group of elements of the shift register, wherein said one or more state values from the first group form a value of a first sequence; and a second output arranged to collect one or more state values from a second group of elements of the shift register, wherein said one or more state values from the second group form a value of a second sequence, and wherein no element of the second group belongs to the first group.