DFT-Spread OFDM Waveform Numerology Alignment

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current wireless communication systems require dedicated hardware to process and decode different types of OFDM waveforms, leading to increased complexity and cost due to misalignment of waveforms with varying numerology over wireless channels.

Innovation Solution

The solution involves scaling and truncating the number of tail zero bits in a DFT-spread OFDM waveform to match the size of another type, allowing for multiplexing and decoding using a shared decoder without the need for separate hardware, thereby aligning the numerology of different OFDM waveforms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If dedicated hardware is used to process and decode different types of OFDM waveforms, then waveform processing capability is improved, but device complexity and cost increase

Engineering Contradiction:

Improvewaveform processing capabilityVSAvoidhardware complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements a universal receiver design where a single receiver can process multiple types of OFDM waveforms (e.g., first type OFDM, second type OFDM with different numerology) by using a shared decoder that can handle different waveform types. This eliminates the need for separate dedicated hardware for each waveform type, reducing device complexity while maintaining versatility.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent combines multiple waveform processing functions into a single integrated receiver structure. By merging the processing of different OFDM waveform types into one receiver with a shared decoder, the system achieves reduced hardware complexity while maintaining the ability to process various waveform types efficiently.

Inventive Principle:

Principle #5Merging (Combining)

2Adaptability or versatility

If different OFDM waveforms with varying numerology are transmitted, then communication flexibility is improved, but waveform alignment and decoding difficulty worsen

Engineering Contradiction:

Improvecommunication flexibilityVSAvoidwaveform alignment and decoding

Core Design Contradiction:

Adaptability or versatilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent employs parameter changes by adjusting the number of tail zero bits in the time-domain signal to align different OFDM waveform types. By modifying this parameter, the system can convert waveforms with different numerology into a unified format that can be processed by a single decoder, reducing decoding difficulty while maintaining communication flexibility.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS9967122B2Techniques for extending an OFDM waveform for multiplexing

Publication Date: 2018.05.08 QUALCOMM INC

AI summary

Aspects of the present disclosure provide systems, methods, and apparatuses for implementing the multiplexing of different orthogonal frequency-division multiplexing (OFDM) waveforms using a transmitter and receiver configured to process different types of signals without a need for distinct hardware structures. In one example, aspects of the present disclosure may include a transmitter configured to transmit both a first type of discrete fourier transform (DFT)-spread OFDM waveform and a second type of DFT-spread OFDM waveform that may be multiplexed over the wireless channel. In some aspects, the transmitter may modify the numerology of the zero-tail DFT-spread OFDM waveform to match the numerology of other OFDM waveforms (e.g., OFDM waveform with zero-guard or a single carrier DFT-spread OFDM with zero-guard).