L1/L2 Control Channel Multiplexing for Broadcast Resource Efficiency

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Solution Overview

Problem

In radio communication systems using multicarrier transmission, the allocation of resource blocks to a broadcast channel results in inefficiency of the L1/L2 control channel, leading to resource wastage when it is not used for the broadcast channel, as it is fixed with a specific modulation scheme and coding rate, and lacks Hybrid Automatic Repeat Request (H-ARQ) functionality.

Innovation Solution

The L1/L2 control channel is multiplexed into a subframe to transmit data on a shared data channel, incorporating update flags, allocation information, and L3 control information, allowing dynamic allocation of resource blocks to the broadcast channel and reducing waste by transmitting BCH control information on the L1/L2 control channel, thereby optimizing resource usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If resource blocks are allocated to the broadcast channel with fixed modulation scheme and coding rate, then the broadcast channel can be transmitted reliably, but the L1/L2 control channel becomes inefficient and resources are wasted when it is not used

Engineering Contradiction:
Improvebroadcast channel transmission reliabilityVSAvoidL1/L2 control channel resource wastage
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent merges the L1/L2 control channel with the broadcast channel by multiplexing L1/L2 control information into the broadcast channel's L1/L2 control region. This allows the L1/L2 control channel to be efficiently utilized even when resource blocks are allocated to the broadcast channel, eliminating the resource wastage while maintaining broadcast channel reliability through fixed modulation and coding rate

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The L1/L2 control channel is designed to serve multiple functions: it controls both the shared data channel and the broadcast channel. By transmitting broadcast channel control information (BCH control information) through the L1/L2 control channel, the system achieves multi-functionality, allowing the same control channel infrastructure to support both unicast and broadcast operations without resource wastage

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

2Productivity

If the L1/L2 control channel is used to transmit control information for shared data channel, then data transmission efficiency is improved, but the control channel cannot be used for broadcast channel when resource blocks are allocated to broadcast channel

Engineering Contradiction:
Improvedata transmission efficiencyVSAvoidcontrol channel adaptability
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The L1/L2 control channel is designed to serve multiple functions: it controls both the shared data channel and the broadcast channel. By transmitting broadcast channel control information (BCH control information) through the L1/L2 control channel, the system achieves multi-functionality, allowing the same control channel infrastructure to support both unicast and broadcast operations without resource wastage

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

Solution Approach 2:

The system dynamically allocates control information types within the L1/L2 control channel based on whether resource blocks are allocated to the broadcast channel. When broadcast channel resource block allocation occurs, the L1/L2 control channel dynamically switches to transmit BCH control information instead of shared data channel control information, enabling flexible adaptation to different operational modes

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2034758B1Base station, mobile station, and communication method
Publication Date: 2014.04.23 NTT DOCOMO INC
  • EP2034758B1 patent drawingFigure 1
  • EP2034758B1 patent drawingFigure 2
  • EP2034758B1 patent drawingFigure 3

AI summary

A base station for transmitting a radio frame where an L1/L2 control channel is multiplexed into a portion of a subframe to transmit data on a shared data channel includes a broadcast channel generating unit configured to generate a broadcast channel; an L1/L2 control channel generating unit configured to generate the L1/L2 control channel corresponding to the broadcast channel, which includes at least one broadcast channel control information from the group consisting of: an update flag indicating whether information on the broadcast channel is modified, broadcast channel allocation information, and L3 control information for the broadcast channel; and a multiplexing unit configured to multiplex the broadcast channel, the shared data channel, and the L1/L2 control channel into the subframe.