Adaptive IQ Stream Quantization for 5G Fronthaul Compression

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Solution Overview

Problem

The high bandwidth requirements of fronthaul links in distributed base station systems, particularly for 5G, lead to capacity bottlenecks due to the need for multiple high-speed fiber and copper cables, which increases transport costs and limits the feasibility of centralized radio access networks (C-RAN).

Innovation Solution

Adapting the amplitude range of the quantizer and selecting an appropriate entropy encoding dictionary based on signal quality to finely tune the compression rate, allowing for continuous adjustment of data transmission capacity and quality, rather than discrete steps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the bandwidth of fronthaul links is increased to meet 5G requirements, then the transmission capacity is improved, but the transport cost increases dramatically

Engineering Contradiction:
Improvetransmission capacityVSAvoidtransport cost
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The invention extracts and removes redundant information from IQ samples through various processing techniques including removing cyclic prefix, downsampling, and entropy encoding. This extraction of unnecessary data reduces the bandwidth requirement of fronthaul links while maintaining the essential signal information needed for communication, thereby reducing transport costs without sacrificing transmission capacity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes multiple parameters of the IQ samples including sampling rate, quantization bits, and encoding schemes. By dynamically adjusting these parameters based on network conditions and signal quality requirements, the system optimizes the balance between transmission capacity and transport cost, enabling cost-effective deployment of high-bandwidth 5G networks.

Inventive Principle:
Principle #35Parameter changes

2Quantity of substance

If compression is applied to reduce fronthaul bandwidth requirements, then transport cost is reduced, but signal quality deteriorates

Engineering Contradiction:
Improvefronthaul bandwidthVSAvoidsignal quality
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The invention introduces dynamic adjustment mechanisms that adapt compression parameters based on real-time signal quality requirements and network conditions. The system can dynamically change the degree of compression, sampling rate, and quantization precision to maintain acceptable signal quality while optimizing bandwidth usage, thereby resolving the trade-off between compression and signal quality.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention implements feedback mechanisms where the system monitors signal quality metrics and adjusts compression parameters accordingly. This closed-loop control ensures that compression is applied within acceptable quality thresholds, allowing the system to maintain reliability while reducing fronthaul bandwidth requirements through intelligent parameter adjustment.

Inventive Principle:
Principle #23Feedback

3Device complexity

If discrete compression rates are used, then implementation is simplified, but adaptability to dynamic network conditions is limited

Engineering Contradiction:
Improveimplementation complexityVSAvoidcompression rate adaptation
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The invention transforms the static, discrete compression rate selection into a dynamic, continuous adjustment mechanism. By enabling real-time modification of compression parameters based on network conditions and signal quality, the system achieves fine-grained adaptability while maintaining implementation feasibility through standardized processing blocks that can be dynamically configured.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3549287B1Methods, encoder and decoder for handling a data stream for transmission between a remote unit and a base unit of a base station system
Publication Date: 2025.07.23 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3549287B1 patent drawingFigure 1~2
  • EP3549287B1 patent drawingFigure 3~4
  • EP3549287B1 patent drawingFigure 5~6

AI summary

Described is a method performed by an encoder of a base station system (100) of a wireless communication network, for handling a data stream comprising a number of consecutive IQ samples for transmission over a transmission network (165) between a remote unit (160) and a base unit (170) of the base station system. The remote unit (160) is arranged to transmit wireless signals to and receive from mobile stations (180), each of the number of IQ samples comprising a first number of bits. The method comprises quantizing, by a quantizer, the IQ samples or IQ prediction errors of the IQ samples with a second number of bits, wherein an amplitude range of the quantizer for the second number of bits is variable and set based on an acceptable signal quality value, entropy encoding the quantized IQ samples or IQ prediction errors applying a first entropy encoding dictionary out of a plurality of entropy encoding dictionaries, based on the set amplitude range of the quantizer, and transmitting, to a decoder, the entropy encoded and quantized IQ samples or IQ prediction errors over the transmission network.