Structured Superposition Coding for Grant-Free IoT Access

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Solution Overview

Problem

Conventional wireless communication networks face performance degradation and increased latency when handling a large number of user devices, particularly IoT devices, due to the inefficiencies of contention-based random access procedures, which result in high signaling overhead and access delays.

Innovation Solution

The implementation of a transmitter and receiver system using structured superposition coding, where each user has a unique set of vectors for encoding and decoding data, allowing simultaneous initial access and communication by linearly combining sequences, and enabling grant-free or grant-less uplink, downlink, and device-to-device transmissions, reducing latency and accommodating a large number of devices without requiring channel knowledge.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If contention-based random access procedures are used for initial access, then user devices can access the network, but signaling overhead increases and access latency increases

Engineering Contradiction:
Improvenetwork access capabilityVSAvoidaccess latency
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The patent applies preliminary action by pre-configuring unique vector sets for each user device before actual data transmission. During initial access, devices can directly use these pre-assigned vectors for encoding without undergoing lengthy contention-based random access procedures, thereby reducing access latency while maintaining network access capability

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent extracts the access request and data transmission into a unified process. By using structured superposition coding with pre-assigned unique vectors, the system eliminates the separate contention resolution phase, allowing devices to transmit both access requests and data simultaneously, thus reducing signaling overhead and access time

Inventive Principle:
Principle #2Taking out (Extraction)

2Ease of operation

If contention-based random access procedures are used for initial access, then user devices can access the network, but signaling overhead increases

Engineering Contradiction:
Improvenetwork access capabilityVSAvoidsignaling overhead
Core Design Contradiction:
Ease of operationVSLoss of information

Solution Approach 1:

The patent merges initial access signaling and data transmission into a single unified process. By using structured superposition coding where unique vectors encode both device identification and data, the system eliminates redundant access request messages and contention resolution signaling, thereby reducing signaling overhead while maintaining network access capability

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent applies universality by designing unique vectors that serve multiple functions simultaneously: they identify the transmitting device, encode the access request, and carry the actual data payload. This multi-functionality eliminates the need for separate signaling messages, reducing overall signaling overhead

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Ease of operation

If conventional access mechanisms are used, then network access is provided, but the number of supported devices is limited

Engineering Contradiction:
Improvenetwork accessVSAvoiddevice support capacity
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The patent transitions from traditional time-domain or frequency-domain multiplexing to a high-dimensional vector space for device identification and data encoding. Each device is assigned a unique vector from a large-dimensional space, enabling the system to support a vastly increased number of devices simultaneously without additional signaling overhead, as the vector dimensionality provides a scalable identification space

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

Data Source

PatentEP3662597B1Transmission of data by multiple users over shared resources based on structured superposition coding
Publication Date: 2022.03.16 FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV
  • EP3662597B1 patent drawingFigure 1
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  • EP3662597B1 patent drawingFigure 3

AI summary

A transmitter (UE) for transmitting data to a receiver (BS) of a wireless communication network is disclosed. The wireless communication network includes a plurality of resource elements, and at least a subset of the plurality of resource elements is shared by a plurality of transmitters (UEs) for transmitting data from the plurality of transmitters (UEs) to the receiver (BS). The transmitter (UE) includes at least one antenna, an encoder and a transceiver coupled to the encoder and to the antenna. The encoder receives a data element to be transmitted to a receiver (BS) of the wireless communication network, and maps the data element to a codeword. The codeword is obtained by selecting at least one vector from a unique set of vectors. The unique set of vectors is exclusively assigned to the transmitter (UE), and each vector includes a plurality of symbols. Each symbol is to be transmitted over a resource element of the wireless communication network. The transceiver transmits via the antenna the codeword on the subset of resource elements, and the codeword represents the data element and identifies the transmitter at the receiver (BS).