Cyclic Prefix Processing in Modem Digital Interface

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In Orthogonal Frequency Division Multiplexing (OFDM) communications systems, such as LTE, the increased data throughput and reliability requirements lead to higher power consumption and complexity in the digital interface between baseband and RF ICs, necessitating optimizations that come with negative financial and technical implications.

Innovation Solution

A modem apparatus with a hardware subsystem configured for OFDM, featuring converter components for domain and format conversions, a cyclic prefix processing component, and a digital interface, which reduces data transfer across the interface by processing and storing cyclic prefix data efficiently, thereby minimizing power consumption and latency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If data throughput is increased to support LTE-Advanced optimisations such as MIMO and carrier aggregation, then wireless communications reliability is improved, but power consumption and complexity of the digital interface increase

Engineering Contradiction:

Improvewireless communications reliabilityVSAvoidpower consumption of digital interface

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The cyclic prefix processing function is extracted from the baseband IC and relocated to the RF IC. This extraction removes the computational burden of cyclic prefix processing from the baseband digital interface, thereby reducing power consumption and complexity while maintaining the reliability benefits of LTE-Advanced features

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces an intermediate processing stage where the cyclic prefix is processed within the RF IC before digital-to-analogue conversion. This intermediary approach allows the system to maintain high data throughput for reliable communications while avoiding the need to transfer and process cyclic prefix data through the power-consuming digital interface

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If data throughput is increased to support LTE-Advanced optimisations such as MIMO and carrier aggregation, then wireless communications reliability is improved, but complexity of the digital interface increases

Engineering Contradiction:

Improvewireless communications reliabilityVSAvoidcomplexity of digital interface

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The cyclic prefix processing function is extracted from the baseband IC and relocated to the RF IC. This extraction reduces the number of processing stages that require digital interface support, thereby reducing interface complexity while maintaining reliability

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent segments the modem functionality into distinct processing stages: cyclic prefix processing is performed in the RF IC before digital-to-analogue conversion, while the baseband IC handles higher-layer processing. This segmentation reduces the data burden on the digital interface, lowering complexity

Inventive Principle:

Principle #1Segmentation

3Productivity

If cyclic prefix processing is performed in baseband IC, then data processing is complete, but data transfer across digital interface increases power consumption

Engineering Contradiction:

Improvedata processing completenessVSAvoidpower consumption of digital interface

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

The cyclic prefix processing is extracted from the baseband IC and performed in the RF IC. This allows the baseband IC to focus on higher-layer processing while the RF IC handles the cyclic prefix, reducing the volume of data that must be transferred across the power-consuming digital interface

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The cyclic prefix is processed in advance within the RF IC before the signal undergoes digital-to-analogue conversion. This preliminary action ensures that cyclic prefix processing is completed without requiring additional data transfers across the digital interface, thereby reducing power consumption

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS10250423B2Modem apparatus, communications system and method of processing a cyclic prefix

Publication Date: 2019.04.02 U-BLOX

AI summary

A modem apparatus is configured to provide wireless network access in accordance with an Orthogonal Frequency Division Multiplexing communications scheme. The apparatus comprises a hardware subsystem comprising baseband processing components (302) and Radio Frequency processing components (304). The baseband processing components (302) comprise a first converter component (314) arranged to convert between time and frequency domains in accordance with the Orthogonal Frequency Division Multiplexing communications scheme, and a second converter component (316) arranged to convert between parallel and serial data formats, the second converter (316) being operably coupled to the first converter (314). The Radio Frequency processing components (304) comprise a cyclic prefix processing component (318) responsive to control information. A digital interface (306) is disposed between the baseband processing components (302) and the RF processing components (304), the digital interface (306) being operably coupled to the second converter (316) and the cyclic prefix processing component (318).