Wireless Transmitter Zero-Power Multiplexing for Mixed Waveforms

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Solution Overview

Problem

Efficient multiplexing of signals using different waveforms in a wireless communication system is challenging, particularly in environments with high Doppler shifts and varying user capabilities.

Innovation Solution

A transmitter design that allocates zero power resources in the time-frequency domain for non-orthogonal multiplexing of signals, utilizing power shaping in the delay-doppler domain and sparse mapping in the time-frequency domain to enhance compatibility and reduce interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If signals using different waveforms are multiplexed, then waveform diversity and adaptability are improved, but multiplexing efficiency and interference management deteriorate

Engineering Contradiction:
Improvewaveform diversityVSAvoidmultiplexing efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The time-frequency resource is divided into two distinct sets: first resources allocated to the first signal and second resources allocated to the second signal. This segmentation allows different waveforms to coexist without mutual interference while maintaining efficient resource utilization, resolving the contradiction between waveform diversity and multiplexing efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a third dimension by allocating resources in both time and frequency domains simultaneously. The first signal uses first time resources and first frequency resources, while the second signal uses second time resources and second frequency resources. This multi-dimensional resource allocation enables efficient multiplexing of different waveforms without interference.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If non-orthogonal multiplexing is used, then spectral efficiency is improved, but interference between signals increases

Engineering Contradiction:
Improvespectral efficiencyVSAvoidinterference
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

Different quality characteristics are assigned to different resource sets. The first resources are configured with parameters suitable for the first waveform, while the second resources are configured with parameters suitable for the second waveform. This local optimization of resource quality allows non-orthogonal multiplexing with reduced interference.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent introduces zero-power resources as an intermediary element between the first and second signals. These resources are allocated to one signal but configured with zero power, effectively acting as a buffer or separator that reduces direct interference while still enabling spectral efficiency through non-orthogonal multiplexing.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4679742A1Transmitter and transmission method
Publication Date: 2026.01.14 NTT DOCOMO INC
  • EP4679742A1 patent drawingFigure 1
  • EP4679742A1 patent drawingFigure 2
  • EP4679742A1 patent drawingFigure 3~4

AI summary

A transmitter includes a control unit configured to allocate zero power resources in a first signal in a time-frequency domain; and a transmission unit configured to non-orthogonally multiplex the first signal and a second signal and transmit the multiplexed signal, wherein the transmission unit is configured to transmit, in the resources in which the zero power resources are allocated, all of at least one repeated transmission among a plurality of repeated transmissions included in the second signal.