OFDMA PDCCH Resource Allocation via CCE Index Encoding
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Solution Overview
Problem
Conventional resource allocation methods in OFDMA-based mobile communication systems face inefficiencies due to increased information overhead when allocating resources across multiple frequency bands, particularly in LTE and LTE-A systems, which complicates the discrimination of frequency bands.
Innovation Solution
The method involves transmitting multiple Physical Downlink Control Channels (PDCCHs) with Control Channel Element (CCE) indices from the base station and modulating them at the user equipment to identify resources allocated in multiple frequency bands through CCE index analysis, allowing resource allocation across multiple frequency bands without additional control information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple PDCCHs with additional frequency band discrimination information are transmitted, then resource allocation across multiple frequency bands is enabled, but control information overhead increases
Solution Approach 1:
The CCE indices themselves serve dual purposes: they identify the PDCCH resources and simultaneously encode the frequency band information. The system uses the existing CCE index structure to convey band discrimination information without requiring separate dedicated fields, making the system self-sufficient in terms of information encoding.
Solution Approach 2:
The patent changes the interpretation parameters of existing CCE indices by applying modulo operations and offset calculations based on the number of frequency bands. Instead of adding new information fields, the system transforms the existing index values to encode both resource location and frequency band identification, thereby reducing overall information overhead.
2Ease of operation
If individual PDCCHs are transmitted for each frequency band, then resource allocation is simplified per band, but the number of control channels increases
Solution Approach 1:
The patent merges multiple frequency band allocations into a single aggregated PDCCH transmission. By combining the resource allocation information for multiple bands into one control channel structure, the system reduces the total number of PDCCH transmissions while maintaining the ability to allocate resources across different frequency bands through the aggregated structure.
Solution Approach 2:
The aggregated PDCCH structure serves multiple functions simultaneously: it allocates resources for multiple frequency bands, identifies the target bands through encoded CCE indices, and maintains compatibility with existing LTE control channel processing. This multi-functional approach eliminates the need for separate dedicated PDCCHs for each band.
3Device complexity
If a single PDCCH is used for all frequency bands, then control channel quantity is reduced, but information overhead for band discrimination increases
Solution Approach 1:
The CCE indices serve themselves dual purposes by simultaneously indicating resource allocation and frequency band identification. The existing index structure is leveraged to encode band information without requiring additional dedicated fields, making the system self-sufficient and eliminating the need for separate band discrimination information.
Solution Approach 2:
The patent transforms the parameter interpretation of CCE indices through mathematical operations (modulo and offset calculations) based on the number of frequency bands. This parameter transformation allows the same index values to convey both resource location and band identification information efficiently, reducing overall information overhead while maintaining a single aggregated PDCCH structure.
Data Source
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AI summary
A resource allocation method and apparatus for an OFDMA-based mobile communication system that allows allocating resources of multiple carriers is provided. A Physical Downlink Control Channel (PDCCH) transmission method for allocating resources in multiple frequency bands of a mobile communication system based on an Orthogonal Frequency Division Multiple Access (OFDMA) according to the present invention includes generating and transmitting, at a base station, multiple PDCCHs for allocating resources in the multiple frequency bands using Control Channel Element (CCE) indices; and receiving and demodulating, at a user equipment, the multiple PDCCHs transmitted by the base station and locating the resources allocated in the multiple frequency bands using the CCE indices of respective PDCCHs. A Physical Downlink Control Channel (PDCCH) transmission apparatus for allocating resources in multiple frequency bands of a mobile communication system based on an Orthogonal Frequency Division Multiple Access (OFDMA) according to the present invention includes a base station apparatus which generates and transmits multiple PDCCHs for allocating resources in the multiple frequency bands using Control Channel Element (CCE) indices; and a user equipment which receives and demodulates the multiple PDCCHs transmitted by the base station and locates the resources allocated in the multiple frequency bands using the CCE indices of respective PDCCHs.