MIMO Control Signal Timing Shift for Legacy Compatibility

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Solution Overview

Problem

In MIMO systems, the inconsistent timing shifts applied to MIMO control signals and MIMO known signals can lead to errors in weight estimation and increased probability of signal errors, particularly in the transmission of control signals, which are critical for data transmission accuracy.

Innovation Solution

A radio apparatus is designed to generate packet signals where the control signal in the leading combination is assigned posterior to the known signal in the time domain, and at least one subsequent combination has a known signal appended, with a cyclic timing shift applied to the control signal to match the timing shift of the known signal, ensuring consistent timing shifts for both control and data signals across combinations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If different timing shifts are applied to MIMO control signals and MIMO known signals, then the packet signal structure can accommodate legacy system compatibility, but the weight estimation accuracy deteriorates and signal error probability increases

Engineering Contradiction:
Improvelegacy system compatibilityVSAvoidweight estimation accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent applies different timing shift strategies to different signal components: MIMO control signals in the leading combination use the same timing shift as legacy known signals for compatibility, while MIMO control signals in remaining combinations use timing shifts matching their corresponding MIMO known signals for accuracy. This local differentiation resolves the contradiction between legacy compatibility and estimation precision.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent segments MIMO control signals into two groups: those in the leading combination and those in remaining combinations. Each segment is assigned different timing shift values appropriate to its function and position, allowing the system to simultaneously satisfy legacy compatibility requirements and MIMO performance requirements.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If MIMO control signals are assigned to a single stream, then the device complexity is reduced, but the power fluctuation increases and transmission reliability deteriorates

Engineering Contradiction:
Improvesignal processing complexityVSAvoidtransmission reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent merges MIMO control signals with data signals in multiple streams, where each stream contains both control and data components. This merging approach distributes power across multiple streams, reducing power fluctuation and improving transmission reliability while maintaining manageable processing complexity through unified stream structure.

Inventive Principle:
Principle #5Merging (Combining)

3Stability of the object's composition

If cyclic timing shift is applied to reduce power fluctuation, then the power stability is improved, but the signal correlation increases and separation accuracy deteriorates

Engineering Contradiction:
Improvepower stabilityVSAvoidsignal separation accuracy
Core Design Contradiction:
Stability of the object's compositionVSMeasurement precision

Solution Approach 1:

The patent carefully selects and adjusts the cyclic timing shift parameter values to achieve an optimal balance: small enough to maintain power stability across streams, but large enough to preserve sufficient signal orthogonality for accurate separation. This parameter optimization resolves the contradiction between power stability and separation accuracy.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP1927216B1Radio apparatus and communication system utilizing the same
Publication Date: 2014.12.24 HERA WIRELESS
  • EP1927216B1 patent drawingFigure 1
  • EP1927216B1 patent drawingFigure 2
  • EP1927216B1 patent drawingFigure 3A~3C

AI summary

In a combination of control signals on data signals and the data signals where the combination contains data signals to be assigned respectively to a plurality of streams, a control unit assigns a control signal contained in a leading combination and assigns a data signal, contained in the leading combination, to a position posterior to the assigned control signal. The control unit appends a known signal to at least one of the remaining combinations and then assigns sequentially the remaining combinations to a position posterior to the assigned data signal so as to generate packet signals.