Uplink Multi-Point Cooperation Delay Management
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Solution Overview
Problem
In multi-point cooperation wireless communication systems, the increase in the number of base stations participating in cooperation leads to an increase in delay spread, necessitating a longer cyclic prefix to prevent interference, which results in radio resource overhead and a trade-off between performance gain and overhead.
Innovation Solution
A method is introduced where the serving base station determines an extended cyclic prefix length based on the propagation delay and delay spread values, selecting cooperation base stations that maximize multi-point gain while minimizing overhead, by grouping terminals with similar delay attributes into specific cooperation zones and applying appropriate frame formats to prevent inter-symbol and inter-channel interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the number of base stations participating in multi-point cooperation is increased, then the multi-point cooperation gain is improved, but the delay spread increases and the cyclic prefix length must be increased causing radio resource overhead
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the cyclic prefix length based on the actual delay spread characteristics of different base station groups. Instead of using a uniformly extended cyclic prefix for all cooperation base stations, the system calculates the delay spread for each group and sets the cyclic prefix length accordingly (L_CP ≥ max(Delay_Spread)), thereby reducing the overhead while maintaining the ability to prevent inter-symbol and inter-channel interference in multi-point cooperation scenarios.
2Reliability
If a longer cyclic prefix is used to prevent inter-symbol and inter-channel interference, then the interference prevention is improved, but the radio resource overhead increases
Solution Approach 1:
The patent applies local quality by differentiating the cyclic prefix length requirement for different groups of base stations based on their specific delay spread characteristics. The system divides cooperation base stations into multiple groups, each with its own delay spread calculation and corresponding cyclic prefix length setting. This allows each group to have optimized interference protection tailored to its specific propagation conditions, rather than applying a uniform conservative setting to all base stations.
3Reliability
If the cyclic prefix length is increased to accommodate larger delay spread, then the delay spread coverage is improved, but the effective data transmission time is reduced
Solution Approach 1:
The patent applies parameter changes by dynamically setting the cyclic prefix length parameter based on the calculated delay spread of each base station group. The system determines the minimum necessary cyclic prefix length (L_CP ≥ Delay_Spread) for each group and applies this optimized parameter, thereby maximizing the effective data transmission time while ensuring adequate coverage of the delay spread characteristics for reliable interference-free reception.
Data Source
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AI summary
A method of performing an uplink multi-point cooperation at a serving base station of a wireless communication system, the method comprising: receiving uplink cooperation data from uplink cooperation terminals; receiving, from a cooperation base station, uplink cooperation data of each of the uplink cooperative terminals received at the cooperation base station; receiving, from the cooperation base station, a delay attribute of each of the uplink cooperation terminals calculated at the cooperation base station; and scheduling the uplink cooperation terminals so that the uplink cooperation terminals having a similar delay attribute are located in the same uplink cooperation zone.