Polar Code Frozen-Bit Masking for Lower False Alarms

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Solution Overview

Problem

Polar codes in wireless communication systems face challenges in reducing error detection rates and false alarm rates, particularly due to the similarity of UE-IDs among different users, leading to increased false alarms when using UE-specific sequences for frozen sub-channels.

Innovation Solution

Introducing increased randomness in the sequences applied to frozen sub-channels by combining UE-specific information with cell-specific and time-related parameters, and utilizing a pseudo-random number generator initialized with a seed based on these parameters to generate a mask sequence for polar-coded codewords.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If UE-specific sequences are used for frozen sub-channels, then error correction performance is improved, but false alarm rates increase due to similarity of UE-IDs among different users

Engineering Contradiction:
Improveerror correction performanceVSAvoidfalse alarm rates
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the parameters used to generate frozen bit sequences from only UE-specific parameters to a combination including cell-specific parameters and time parameters. This parameter expansion increases the diversity and randomness of frozen bit sequences, reducing false alarms while maintaining error correction performance through the polar code structure.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If UE-IDs are used as mask sequences for frozen bits, then user-specific error detection is enhanced, but collisions increase when UE-IDs are similar

Engineering Contradiction:
Improveuser-specific error detectionVSAvoidcollision resistance
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent merges multiple parameter types (UE-specific parameters, cell-specific parameters, and time parameters) into a unified seed generation process for the pseudo-random number generator. This combination creates more distinctive mask sequences that maintain user-specific detection capability while significantly reducing collisions between users with similar UE-IDs.

Inventive Principle:
Principle #5Merging (Combining)

3Object-generated harmful factors

If random sequences are applied to frozen sub-channels, then false alarm rates are reduced, but complexity of sequence generation increases

Engineering Contradiction:
Improvefalse alarm ratesVSAvoidsequence generation complexity
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent implements self-service by having each user equipment generate its own pseudo-random mask sequences using a pseudo-random number generator initialized with seeds derived from its specific parameters. This distributed generation approach reduces false alarms through increased randomness while avoiding the need for centralized sequence distribution, thereby managing complexity efficiently.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3566347B1Wireless communication with polar codes using a mask sequence for frozen bits
Publication Date: 2022.06.22 QUALCOMM INC
  • EP3566347B1 patent drawingFigure 1
  • EP3566347B1 patent drawingFigure 2
  • EP3566347B1 patent drawingFigure 3

AI summary

Wireless communication devices are adapted to facilitate information sequences included in frozen sub-channels of polar coded transmissions. According to one example, an apparatus can generate a mask sequence based on a plurality of parameters, including at least one of a transmitting-device-specific sequence or a receiving-device-specific sequence. In some examples, the frozen bits may be masked with the mask sequence, and an information block may be encoded utilizing polar coding. In other examples, the mask sequence may be compared to the frozen bits of a received information block, and the received information block may be determined as intended for the apparatus when the mask sequence matches to the frozen bits. Other aspects, embodiments, and features are also included.