Low-Resolution DAC Beamforming for Energy-Efficient 5G MIMO
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Solution Overview
Problem
Current 5G wireless communication systems face challenges in energy efficiency due to high power consumption by digital-to-analog converters (DACs), especially in millimeter wave (mmWave) spectrum, where massive MIMO systems require large numbers of high-resolution ADCs and DACs, leading to increased power hunger and performance losses.
Innovation Solution
Implementing low-resolution digital-to-analog converters (DACs) with reduced bits per sample and sampling rates, combined with signal processing algorithms and circuits to mitigate the impact on key performance indicators, enabling all-digital beamforming and reducing power consumption while maintaining performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high-resolution DACs with high sampling rates are used in 5G mmWave systems, then signal quality and performance are improved, but power consumption increases significantly
Solution Approach 1:
The patent changes the resolution parameter of DACs from traditional high-resolution (12-14 bits) to low-resolution (4-6 bits), and adjusts sampling rates accordingly. This parameter change enables massive MIMO systems to operate with reduced power consumption while maintaining acceptable signal quality through compensation techniques.
Solution Approach 2:
The patent introduces digital pre-distortion and digital post-processing as intermediary processing stages between the low-resolution DAC and the antenna. These intermediary processing blocks compensate for the quantization errors introduced by low-resolution DACs, effectively mediating between the reduced hardware resolution and the requirement for high signal quality.
2Productivity
If massive numbers of transceiver chains are deployed for massive MIMO, then system capacity and spectral efficiency are improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts the beamforming functionality from the digital domain and moves it to the analog domain using Phase Shift Keying (PSK) modulation. This extraction reduces the number of required transceiver chains from hundreds to a manageable number, while still enabling massive MIMO system capacity through the large number of antennas.
Solution Approach 2:
The patent segments the signal processing into distinct phases: digital precoding, PSK modulation for analog beamforming, and digital post-processing. This segmentation allows the system to achieve massive MIMO capacity without requiring full digital processing for all antenna elements, thereby reducing overall system complexity.
3Use of energy by stationary object
If low-resolution DACs are used, then power consumption and cost are reduced, but signal quality and performance indicators deteriorate
Solution Approach 1:
The patent implements digital post-processing that uses feedback from the received signal to compensate for quantization errors. The system continuously monitors signal quality and adjusts processing parameters to maintain performance indicators at acceptable levels despite the low-resolution DAC.
Solution Approach 2:
The patent applies digital pre-distortion before the signal reaches the low-resolution DAC to pre-compensate for expected quantization errors. This preliminary action ensures that the quantization process introduces minimal distortion, maintaining signal quality while using low-resolution hardware.
4Measurement precision
If high sampling rates are used, then signal accuracy is improved, but energy consumption and processing requirements increase
Solution Approach 1:
The patent uses partial sampling at reduced rates combined with intelligent signal processing that recovers the necessary signal accuracy from the undersampled data. This partial action approach achieves sufficient signal accuracy for communication purposes while consuming significantly less energy than full-rate sampling would require.
Data Source
AI summary
Facilitating energy-efficient wireless communications for advanced networks (e.g., 4G, 5G, and beyond) with low-resolution digital-to-analog converters is provided herein. Operations of a system can comprise determining first values. Respective values of the first values can be digital samples of transmission and reception chains determined based on symbols transformed from bits. The operations can also comprise facilitating a quantization of the first values resulting in second values. Facilitating the quantization can be based on a cost function associated with processing the first values. Further, the operations can comprise outputting the second values as a continuous time signal over antennas of a base station device. The second values can comprise fewer values than the first values.