LTE TDD Special Subframe PUSCH and PHICH Resource Allocation
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Solution Overview
Problem
The time division duplex manner in TDD systems limits the number of subframes available for uplink data transmission, resulting in low uplink throughput.
Innovation Solution
Increasing the number of UpPTS symbols by adjusting the length of the special subframe's guard period and Uplink Pilot Time Slot, allowing additional resources for the Physical Uplink Shared Channel (PUSCH) transmission, and determining the position and time-frequency resource of the Physical Hybrid-ARQ Indicator Channel (PHICH) to improve decoding accuracy using ACK/NACK-based HARQ technology.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If time division duplex manner is used for uplink transmission in TDD system, then downlink and uplink subframes are separated in time, but the quantity of subframes available for uplink data transmission is limited resulting in low uplink throughput
Solution Approach 1:
The special subframe is made multi-functional by allowing it to serve both traditional purposes ( DwPTS for downlink, GP for guard, UpPTS for uplink pilot) and a new function (PUSCH for uplink data transmission). This enables the same time resource to contribute to both downlink and uplink throughput, effectively increasing the quantity of subframes available for uplink data without requiring additional time resources.
2Productivity
If the number of UpPTS symbols is increased to allow additional PUSCH transmission resources, then uplink throughput is improved, but the length of guard period and special subframe structure must be adjusted
Solution Approach 1:
The patent introduces dynamic configuration of special subframe structures through different uplink-downlink subframe configurations (0-6) and adjustable parameters (mu, subframeOffset). This allows the system to adaptively adjust the number of UpPTS symbols and guard period length based on traffic conditions, achieving high uplink throughput while maintaining manageable complexity through standardized dynamic patterns.
3Reliability
If PHICH resource allocation is determined based on PUSCH transmission in special subframe, then decoding accuracy is improved using ACK/NACK-based HARQ, but resource allocation complexity increases
Solution Approach 1:
The patent establishes specific parameter relationships for PHICH resource allocation in special subframes, including determining PHICH resource index based on PUSCH resource parameters (prb-start, mod12, mod6) and applying configuration-specific offsets (k1, k2). This standardized parameter mapping approach ensures reliable HARQ decoding while controlling allocation complexity through consistent mathematical relationships.
Data Source
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AI summary
The present invention relates to the field of mobile communications technologies, and in particular, to a control channel resource allocation method and apparatus. The method includes: sending, by user equipment UE, a physical uplink shared channel PUSCH in a current special subframe; determining, by the UE according to an uplink resource used to transmit the PUSCH, a physical hybrid automatic repeat request indicator channel PHICH resource corresponding to the PUSCH, where the uplink resource used to transmit the PUSCH includes the current special subframe; and receiving a PHICH on the determined PHICH resource. By means of the method and the apparatus that are provided in the present invention, a problem that when a special subframe is used to transmit an uplink PUSCH, there is no specific solution to determining a receiving position of a downlink PHICH corresponding to the uplink PUSCH is resolved.