Time-Frequency Resource Allocation for Moving Wireless Devices
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Solution Overview
Problem
Existing frequency hopping mechanisms in wireless telecommunications are not adapted for moving communication devices, leading to suboptimal transmission error rates in fast fading frequency selective channels.
Innovation Solution
A method for allocating time and frequency resources that involves obtaining long-term signal-plus-interference to noise ratio information, frequency and time correlation profiles, and computing figures of merit to select sequences that improve transmission quality, specifically considering the position and speed of moving conveyances to enhance data transmission reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If frequency hopping mechanisms are implemented for moving communication devices, then transmission error rate is reduced, but device complexity increases due to need for position and speed tracking
Solution Approach 1:
The system performs preliminary actions by obtaining position and speed information of moving conveyances before allocating time-frequency resources. The processing device predicts future positions and pre-calculates optimal frequency hopping sequences based on these predictions, allowing the system to prepare resource allocation in advance rather than reacting to changing conditions in real-time, thus reducing transmission errors while managing complexity.
Solution Approach 2:
The system applies dynamics by making the frequency hopping sequence adaptive to the motion state of conveyances. The resource allocation changes dynamically based on real-time position and speed information, with the processing device adjusting frequency selections according to predicted future positions of moving devices, enabling the system to track and compensate for motion-induced channel variations.
2Ease of operation
If uniform time and frequency resources allocation is used, then implementation is simple, but transmission quality deteriorates in fast fading channels
Solution Approach 1:
The system applies local quality by allocating time-frequency resources non-uniformly based on local channel conditions. The processing device identifies specific time-frequency slots with better expected signal quality (based on position prediction and channel characteristics) and concentrates resources in those locations, rather than distributing them uniformly. This allows the system to maintain simplicity while improving transmission quality by being selective about where resources are allocated.
3Ease of manufacture
If frequency hopping sequences are optimized for static devices, then implementation is straightforward, but performance deteriorates for moving devices in fast fading channels
Solution Approach 1:
The system overcomes the limitation of static-optimized sequences by performing preliminary prediction of future positions of moving devices. The processing device uses current position and speed information to forecast where devices will be, then generates frequency hopping sequences optimized for those future positions. This preliminary action allows the system to maintain straightforward implementation while achieving reliability for moving devices.
Solution Approach 2:
The system transforms static frequency hopping sequences into dynamic ones by incorporating position and speed information. The processing device continuously updates frequency allocations based on changing motion states, making the hopping sequences adaptive to device movement. This dynamic approach maintains ease of implementation through systematic rules while significantly improving transmission reliability in fast fading channels.
Data Source
AI summary
For allocating time and frequency resources for at least one data transmission via a fast fading frequency selective channel between an access point of a wireless telecommunications network and at least one communication device located in at least one respective moving conveyance, a processing device: obtains long-term SINR information for a set of time and frequency resources; obtains at least one frequency correlation profile; obtains at least one time correlation profile; computes figures of merit for potential sequences of time and frequency resources, based on the obtained long-term signal-plus-interference to noise ratio information and on the obtained time and frequency correlation profiles; selects a sequence that provides a figure of merit that expects reaching a target quality of service for said data transmission(s) or that is the best figure or merit; allowing said data transmission(s) via the selected sequence.