Radio Base Station Resource Allocation for Bandwidth-Guaranteed D2D Users
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Solution Overview
Problem
Current 3GPP LTE specifications lack awareness of communication quality in D2D communication, leading to inappropriate BLER settings for adaptive modulation and coding, which can result in increased radio resource consumption and failure to achieve desired transmission rates for bandwidth-guaranteed users.
Innovation Solution
A radio base station with a controller that allocates radio resources and determines a reduced Modulation and Coding Scheme (MCS) for each bandwidth-guaranteed terminal, increasing resource allocation while maintaining a desired transmission rate, allowing for adaptive modulation and coding in D2D communication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If adaptive modulation and coding is applied to D2D communication with standard BLER set values, then frequency-utilization efficiency is improved, but transmission reliability deteriorates due to increased radio resource consumption and failure to achieve desired transmission rates
Solution Approach 1:
The patent changes the BLER set value parameter from standard values (10% for uplink/downlink) to a smaller value (1% or less) specifically for D2D communication. This parameter change resolves the contradiction by adjusting the MCS determination criterion to ensure more reliable transmission without requiring excessive retransmissions, thereby maintaining frequency-utilization efficiency while achieving desired transmission rates.
Solution Approach 2:
The patent applies different BLER set values for different communication types: standard values (10%) for uplink/downlink communication with retransmission, and reduced values (1% or less) for D2D communication without retransmission. This local differentiation resolves the contradiction by tailoring the reliability parameter to the specific characteristics of each communication type, ensuring D2D transmission reliability while preserving overall system efficiency.
2Reliability
If radio resources are increased for bandwidth-guaranteed terminals, then transmission rate reliability is improved, but resource allocation efficiency deteriorates
Solution Approach 1:
The patent dynamically adjusts the BLER set value based on the communication type and terminal requirements. For bandwidth-guaranteed terminals requiring high reliability, a smaller BLER set value (1% or less) is applied, which allows the system to achieve desired transmission rates with more appropriate resource allocation rather than excessive allocation, thus resolving the contradiction between reliability and resource efficiency.
Solution Approach 2:
The patent performs preliminary determination of the BLER set value based on terminal type (bandwidth-guaranteed or non-bandwidth-guaranteed) before resource allocation. This preliminary action allows the system to pre-calculate appropriate MCS values that will achieve desired transmission rates with optimal resource usage, preventing both under-allocation and over-allocation of radio resources.
Data Source
AI summary
A radio base station (1) determines allocated radio resources and a Modulation and Coding Scheme (MCS) for each of a plurality of bandwidth-guaranteed radio terminals in a manner such that an amount of radio resources to be allocated to each bandwidth-guaranteed radio terminal is increased and the MCS to be set for each bandwidth-guaranteed radio terminal is reduced as far as possible within a range that allows a transmission rate of each bandwidth-guaranteed radio terminal obtained after the radio resources are allocated to the plurality of bandwidth-guaranteed radio terminals to achieve a desired transmission rate. Accordingly, for example, it is possible to provide adaptive modulation and coding that allows a bandwidth-guaranteed user to achieve a desired transmission rate (or that makes it possible to increase a probability of achieving a desired transmission rate).