MIMO Feedback Signaling CRC Checks for Precoding Reliability

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current wireless communication systems lack effective error checking and detection capabilities in feedback signaling, leading to significant degradation of link and system performance, particularly in MIMO systems, where feedback errors can severely impact precoding and channel quality index validation.

Innovation Solution

Implementing error check bits, such as cyclic redundancy check (CRC) bits, attached to feedback signals like PMI, CQI, and ACK/NACK, and coding them with data bits using various channel coding schemes to ensure reliable transmission and detection, thereby enhancing error checking and detection capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If error check bits are attached to feedback signals, then reliability of feedback signaling is improved, but device complexity increases

Engineering Contradiction:

Improvefeedback signaling reliabilityVSAvoidsignaling structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Error check bits are attached to feedback signals before transmission to proactively detect potential errors. The CRC bits are calculated and appended in advance at the transmitter side, enabling error detection before the feedback signal is processed by the receiver, thus preventing error propagation.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Cyclic redundancy check (CRC) bits serve as an intermediary mechanism between the feedback signal and the receiver's validation process. The CRC bits act as a mediator that carries error detection information without being part of the original feedback data, allowing error checking to be performed separately and efficiently.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If error detection capability is added to feedback signaling, then system performance is improved, but overhead increases

Engineering Contradiction:

Improvelink performanceVSAvoidsignaling overhead

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

Instead of implementing comprehensive error correction codes that would require extensive overhead, the patent applies a lighter CRC-based error detection mechanism. This partial action approach provides sufficient error detection capability for feedback signals without the excessive overhead of full error correction, balancing reliability improvement with overhead constraints.

Inventive Principle:

Principle #16Partial or excessive action

3Measurement precision

If CRC bits are appended to feedback signals, then error detection capability is improved, but productivity decreases

Engineering Contradiction:

Improveerror detection accuracyVSAvoidsignal processing efficiency

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The error detection function is extracted as a separate CRC calculation and validation process, distinct from the main feedback signal processing. The CRC bits are calculated separately and appended to the feedback signal, allowing the core feedback processing to remain efficient while adding error detection capability as an independent, optimized function.

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentUS9048998B2Feedback signaling error detection and checking in MIMO wireless communication systems

Publication Date: 2015.06.02 INTERDIGITAL PATENT HOLDINGS INC

AI summary

A method of feedback in a wireless transmit receive unit includes providing a precoding matrix index (PMI), error checking the (PMI) to produce an error check (EC) bit, coding the PMI and the EC bit and transmitting the coded PMI and EC bit.