Narrow Bandwidth User Terminal Frequency Diversity
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Solution Overview
Problem
Conventional communication systems face challenges in reducing the cost of MTC terminals while maintaining effective cellular system coverage, as they are not designed to handle bandwidth differences between system and shared channel bandwidths, leading to unnecessary communication overhead and difficulties in allocating control signals within narrower bandwidths.
Innovation Solution
A user terminal is configured to operate with a narrow bandwidth that is dynamically allocated at different frequency positions, using enhanced PDCCH and PDSCH allocation methods to improve frequency diversity and reduce DCI overhead, allowing for efficient communication of both data and control signals within a narrower bandwidth than the system bandwidth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional control signal (PDCCH) that assumes system bandwidth and shared channel bandwidth are the same is utilized in a low-cost MTC terminal, then the terminal can operate with existing communication protocols, but the terminal cannot achieve cost reduction and unnecessary communication overhead occurs
Solution Approach 1:
The patent implements dynamic bandwidth adaptation by allowing the terminal to operate with a shared channel bandwidth that is narrower than the system bandwidth. The PDCCH is dynamically allocated within this narrower bandwidth, enabling the terminal to adjust its operational bandwidth according to service requirements rather than being fixed to the full system bandwidth, thus reducing communication overhead while maintaining protocol compatibility.
Solution Approach 2:
The patent applies local quality by creating a localized control region within the narrower shared channel bandwidth. The PDCCH is allocated in this specific local region rather than spanning the entire system bandwidth, allowing the terminal to focus resources on a specific frequency range and reducing overall communication overhead while maintaining effective control functionality.
2Ease of manufacture
If the bandwidth allocated for control signals is reduced, then cost reduction is achieved, but the allocation of control signals and data signals becomes problematic
Solution Approach 1:
The patent segments the frequency spectrum by dividing the system bandwidth into distinct regions: a narrower shared channel bandwidth for data transmission and a control region within this narrower bandwidth for PDCCH allocation. This segmentation allows independent optimization of data and control signal allocation, simplifying the overall signal allocation process while reducing terminal cost through narrower bandwidth operation.
Solution Approach 2:
The patent introduces an additional dimension to signal allocation by separating control and data signals in the frequency domain within the narrower bandwidth. The PDCCH is allocated in specific resource blocks within the narrower shared channel bandwidth, creating a two-layer frequency structure that resolves allocation conflicts and reduces complexity.
3Ease of operation
If control signals and data signals are allocated in the narrow bandwidth in the same manner, then allocation simplicity is maintained, but frequency diversity and resource utilization efficiency deteriorate
Solution Approach 1:
The patent applies local quality by allocating control signals (PDCCH) and data signals (PDSCH/PUSCH) to different local regions within the narrower bandwidth. The control region is specifically designated within the narrower shared channel bandwidth, while data signals occupy remaining resources, creating localized allocation zones that improve frequency diversity and resource utilization while maintaining allocation simplicity.
Solution Approach 2:
The patent implements dynamic resource allocation where the PDCCH can be flexibly positioned within the narrower bandwidth based on channel conditions and traffic requirements. This dynamic allocation allows the system to optimize frequency diversity by placing control signals in frequency regions with better channel characteristics, thereby improving overall frequency utilization efficiency without sacrificing allocation simplicity.
Data Source
Figure 1A~1B
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AI summary
According to the present invention, in an LTE system, communication can appropriately carried out even in the case where a bandwidth utilized in the transmission/receiving of data signals and control signals is configured narrower than the system bandwidth. According to an embodiment, a user terminal is configured to carry out communication with a radio base station using a narrow bandwidth that is limited to a narrower bandwidth than a system bandwidth. The user terminal includes a decision section configured to decide a frequency position for the narrow bandwidth to be arranged, based on given information; and a receiving section configured to receive a control signal and a data signal that are allocated on the narrow bandwidth based on the frequency position. The narrow bandwidth is arranged at different frequency positions per a predetermined period of time.