MIMO Feedback Signaling with PMI Error Check Bits

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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 feedback.

Innovation Solution

Implementing error check bits, such as cyclic redundancy check (CRC) bits, attached to and coded with precoding matrix index (PMI) and other feedback signals, to enable error detection and correction, thereby enhancing the reliability of feedback signaling in wireless communication systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If error check bits are added to feedback signaling, 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 (such as CRC bits) are attached to feedback signaling in advance before transmission. This preliminary action enables the receiving end to detect errors in precoding matrix index (PMI) and channel quality index (CQI) feedback, improving reliability without requiring complex real-time error handling mechanisms.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Error check bits serve as an intermediary element between the transmitter and receiver in the feedback signaling process. These bits mediate the error detection function, allowing the system to identify corrupted feedback signals without requiring complex verification protocols or retransmission mechanisms.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If error detection capability is added to feedback control signaling, then system capacity increases, but loss of information increases

Engineering Contradiction:

Improvesystem capacityVSAvoidfeedback information overhead

Core Design Contradiction:

ProductivityVSLoss of information

Solution Approach 1:

Instead of implementing comprehensive error correction codes that would significantly increase overhead, the patent applies partial error detection using compact check bits (e.g., CRC bits). This provides sufficient error detection capability to identify problematic feedback signals while maintaining minimal overhead, allowing the system to handle errors through simple detection rather than full correction.

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The patent changes the parameter of error protection from none to a minimal level by adding error check bits. This parameter change enables error detection capability while keeping the increase in information overhead small, thus improving system capacity without excessive information loss.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS10318374B2Feedback signaling error detection and checking in MIMO wireless communication systems

Publication Date: 2019.06.11 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.