Blind Distributed Multi-User MIMO Decoding

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Solution Overview

Problem

Current distributed MIMO techniques require coordination between wireless devices and base stations for channel measurements, which is impractical in IoT networks due to power constraints and sporadic device activity, leading to high overhead and inefficiency.

Innovation Solution

A method that allows wireless devices to transmit independently and estimate carrier frequency offsets (CFOs) and channel parameters using known preambles without coordination, transitioning between blind estimation and steady states to decode concurrent transmissions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If distributed MIMO techniques use coordinated channel measurements between wireless devices and base stations, then decoding accuracy of concurrent transmissions is improved, but system overhead and complexity increase significantly

Engineering Contradiction:
Improvechannel estimation accuracyVSAvoidcoordination overhead
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system enables base stations to autonomously estimate channel parameters and CFOs using only received signal data and known preambles, without requiring coordination or active participation from wireless devices. The devices simply transmit their data while the base stations independently perform blind estimation of all necessary parameters.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent extracts the channel measurement and parameter estimation functions from the coordinated device-station interaction and relocates them entirely to the base station side. This eliminates the need for devices to participate in measurement phases, removing the coordination overhead while maintaining estimation capability.

Inventive Principle:
Principle #2Taking out (Extraction)

2Measurement precision

If distributed MIMO implements a measurement phase for channel estimation, then channel parameters are accurately known, but transmission time and network efficiency decrease

Engineering Contradiction:
Improvechannel parameter knowledgeVSAvoidtransmission efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The system performs preliminary channel estimation and CFO detection during the reception of known preambles at the beginning of each transmission, rather than requiring a separate measurement phase. This preliminary action using preamble signals enables accurate parameter knowledge to be established before actual data transmission begins, improving overall efficiency.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The base stations continuously perform blind estimation of channel parameters and CFOs during ongoing transmissions using the received signals and known preambles, rather than interrupting transmission for separate measurement phases. This continuous useful action maintains accurate channel knowledge without sacrificing transmission time.

Inventive Principle:
Principle #20Continuity of useful action

3Measurement precision

If distributed MIMO requires coordination between IoT devices and base stations, then channel measurements are accurate, but power consumption and operational complexity of IoT devices increase

Engineering Contradiction:
Improvechannel measurement accuracyVSAvoidIoT device power consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The base stations independently perform all channel measurement and parameter estimation functions without requiring IoT devices to participate in coordination or measurement activities. Devices simply transmit their data packets while base stations autonomously estimate channel parameters, CFOs, and decode transmissions using blind estimation techniques.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent extracts the channel measurement and parameter estimation functions from the IoT device and relocates them entirely to the base station. This eliminates the need for power-consuming coordination activities, measurement phase participation, and complex device-side processing, significantly reducing IoT device power consumption and operational complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

4Area of stationary object

If distributed MIMO uses narrowband channels for long-range communication, then wireless coverage is extended, but network capacity and throughput are reduced

Engineering Contradiction:
Improvegeographical coverageVSAvoidnetwork capacity
Core Design Contradiction:
Area of stationary objectVSProductivity

Solution Approach 1:

The patent combines signals from multiple base stations receiving concurrent transmissions from different wireless devices using distributed MIMO techniques. By merging the receiving capabilities of multiple base stations and using blind estimation to separate and decode concurrent transmissions, the system increases network capacity and throughput while maintaining long-range narrowband communication.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentUS11171813B2Blind distributed multi-user MIMO for decoding multiple concurrent wireless transmissions
Publication Date: 2021.11.09 MICROSOFT TECHNOLOGY LICENSING LLC
  • US11171813B2 patent drawing
  • US11171813B2 patent drawing
  • US11171813B2 patent drawing

AI summary

Techniques for blind distributed multi-user MIMO enable simultaneous decoding of multiple concurrent wireless transmissions without the need for coordination between wireless devices or a measurement phase. Wireless devices are permitted to transmit independently and at arbitrary times. Concurrent transmissions from wireless devices superimpose in the wireless channel and are received at various base stations. The base stations forward received data samples to a central entity (e.g., a cloud computing service), which uses known preambles to reliably estimate CFOs and channels between the transmitting devices and the receiving base stations while simultaneously recovering the data samples of the individual data streams.