Nested Frequency Hopping for Wireless Uplink Efficiency

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Solution Overview

Problem

In wireless communication systems, especially in NB-IoT and eMTC, frequency hopping procedures often result in wasted time periods for UEs due to interference, as they cannot receive downlink communications, leading to inefficiencies.

Innovation Solution

Implementing a random or pseudorandom frequency hopping procedure within selected downlink carriers for UEs to identify uplink channels, allowing them to transmit even if they cannot receive downlink communications, and using time division multiplexing to manage collisions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If frequency hopping procedure is implemented for NB-IoT and eMTC communications, then interference resistance and coverage are improved, but time efficiency deteriorates due to wasted time periods when UEs cannot receive downlink communications

Engineering Contradiction:
Improveinterference resistanceVSAvoidwasted time periods
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies dynamics by making the frequency hopping procedure adaptive and configurable. The network can dynamically adjust hopping parameters, selectivity levels, and target frequency offsets based on current channel conditions and traffic requirements. This allows the system to optimize between interference resistance and time efficiency in real-time, rather than using a fixed hopping pattern that always prioritizes one aspect over the other.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes key parameters of the frequency hopping procedure, including the selectivity of frequency selection, target frequency offset values, and hopping patterns. By modifying these parameters, the system can reduce the duration of wasted time periods while maintaining interference resistance. Specifically, the network can configure UEs to hop to frequencies with better downlink-uplink interference alignment, reducing the need for prolonged silent periods.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If traditional frequency hopping is used where UEs wait for downlink communications, then downlink reception reliability is improved, but uplink transmission efficiency deteriorates

Engineering Contradiction:
Improvedownlink reception reliabilityVSAvoiduplink transmission efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies preliminary action by having UEs pre-identify suitable uplink transmission frequencies using a pseudorandom selection process before downlink reception attempts. UEs independently select target frequencies based on configured offsets and hopping patterns, preparing transmission resources in advance. This allows UEs to immediately transmit uplink data when ready, without waiting for downlink communication confirmation, thus improving uplink efficiency while maintaining downlink reliability through proper frequency selection.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent enables UEs to self-select uplink frequencies using pseudorandom processes and pre-configured hopping parameters. Each UE independently determines its transmission frequency without requiring explicit network scheduling for each uplink opportunity. This self-service approach allows UEs to efficiently utilize uplink resources autonomously, improving overall system productivity while the network maintains control over the hopping configuration to ensure downlink reception reliability.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3747145B1Nested frequency hopping for data transmission
Publication Date: 2023.12.20 QUALCOMM INC
  • EP3747145B1 patent drawingFigure 1
  • EP3747145B1 patent drawingFigure 2
  • EP3747145B1 patent drawingFigure 3

AI summary

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive a discovery reference signal from a base station on an anchor channel. The UE may perform a first random or pseudorandom frequency hopping procedure to identify a plurality of downlink carriers for a first time period. The UE may perform a second random or pseudorandom frequency hopping procedure within the plurality of downlink carriers to select one of the plurality of downlink carriers as the uplink channel for a second time period. The UE may then transmit an uplink communication during the second time period on the selected uplink channel. In some examples, the uplink communication may be transmitted based at least in part on time division multiplexing (TDM) information.