Hybrid Precoding With Low-Bit ADCs for mmWave MIMO Power Limits

Solution Overview

Problem

The high power consumption of traditional precoding solutions in millimeter wave (mmWave) systems makes precoding/combining processing in the baseband unfeasible due to the high power requirements of mixed-signal components, especially with the need for large antenna arrays and high-resolution digital to analog converters (DACs)/analog-to-digital converters (ADCs).

Innovation Solution

The implementation of hybrid precoding that divides precoding processing between analog and digital domains, using low-bit ADCs and analog-only beamforming with phase shifters, which reduces the number of RF chains and power consumption, and employs adaptive beamforming algorithms and multi-resolution codebooks to minimize training overhead and maximize received signal power.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If traditional precoding solutions with mixed-signal components are used, then precoding/combining processing can be performed in the baseband, but power consumption becomes excessively high

Engineering Contradiction:

Improveprecoding processing capabilityVSAvoidpower consumption

Core Design Contradiction:

Ease of operationVSUse of energy by moving object

Solution Approach 1:

The precoding function is segmented into two separate domains: analog precoding performed by phase shifters in the RF domain, and digital precoding performed by the low-bit ADC in the digital domain. This segmentation allows the system to avoid the high power consumption of traditional mixed-signal baseband processing while retaining both analog and digital precoding capabilities.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent replaces the traditional mechanical/electronic mixed-signal baseband processing system with a hybrid system that substitutes digital signal processing in low-bit ADCs for analog phase manipulation. This substitution dramatically reduces power consumption while maintaining precoding functionality.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Use of energy by moving object

If low-bit ADCs are used for precoding, then power consumption and hardware costs are reduced, but signal processing precision may be compromised

Engineering Contradiction:

Improvepower consumptionVSAvoidsignal processing precision

Core Design Contradiction:

Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The precoding function is segmented into two separate domains: analog precoding performed by phase shifters in the RF domain, and digital precoding performed by the low-bit ADC in the digital domain. This segmentation allows the system to avoid the high power consumption of traditional mixed-signal baseband processing while retaining both analog and digital precoding capabilities.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent changes the precision parameter of the ADC from traditional high-bit resolution to low-bit resolution (1-3 bits), which dramatically reduces power consumption and hardware complexity. The hybrid architecture compensates for the reduced quantization precision through analog phase processing, maintaining overall system performance.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If large antenna arrays are deployed for beamforming, then received link margin is improved, but hardware costs and system complexity increase

Engineering Contradiction:

Improvereceived link marginVSAvoidhardware complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The precoding function is segmented into two separate domains: analog precoding performed by phase shifters in the RF domain, and digital precoding performed by the low-bit ADC in the digital domain. This segmentation allows the system to avoid the high power consumption of traditional mixed-signal baseband processing while retaining both analog and digital precoding capabilities.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent changes the precision parameter of the ADC from traditional high-bit resolution to low-bit resolution (1-3 bits), which dramatically reduces power consumption and hardware complexity. The hybrid architecture compensates for the reduced quantization precision through analog phase processing, maintaining overall system performance.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20170019157A1Hybrid precoding design for multiple input multiple output system with few-bit analog to digital converters

Publication Date: 2017.01.19 SAMSUNG ELECTRONICS CO LTD

AI summary

A mobile device includes a receiver configured to perform hybrid precoding on signals received through a large bandwidth communication. The receiver includes a plurality of antennas configured to receive wireless communications signals through the large bandwidth communication. The receiver also includes a number of radio frequency (RF) chains, each comprising a low-bit analog to digital converter (ADC) configured to preform precoding to receive the data and control signals. The receiver further includes a baseband processor configured to perform baseband detection.