HARQ Redundancy Version Selection for HSDPA Throughput
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Solution Overview
Problem
Current HARQ methods in HSDPA systems require a large number of simulations to select the optimal Redundancy Version (RV) for maximizing throughput, which is inefficient and needs to be performed repeatedly even with changes in system specifications.
Innovation Solution
An apparatus and method that select an RV by considering coding gain and the balance between energy per systematic bit and energy per parity bit, using a controller to set parameter values and prioritize systematic or parity bits based on transmission type and energy ratios, allowing for quick and efficient RV selection without extensive simulations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If simulations are performed for every MCS according to the number of times re-transmission is performed to select the optimal RV, then the system throughput is maximized, but the complexity and time consumption increase significantly
Solution Approach 1:
The patent pre-calculates and stores the optimal RV selection criteria in lookup tables during system initialization or offline preparation. These tables contain pre-determined relationships between MCS levels, re-transmission counts, and optimal RV parameters. During actual operation, the system simply queries these pre-computed tables rather than performing simulations, thereby eliminating the need for real-time simulations while maintaining optimal throughput performance
Solution Approach 2:
The patent transforms the complex simulation problem into a parameter-based lookup approach by identifying key parameters (MCS level, re-transmission count) that determine optimal RV selection. Instead of simulating all possible scenarios, the system changes the approach to using pre-determined parameter mappings stored in lookup tables, where the optimal RV is selected based on matching the current MCS and re-transmission count to pre-stored optimal configurations
2Productivity
If simulations are repeatedly performed to select the optimal RV, then the throughput is maximized, but the time consumption increases
Solution Approach 1:
The patent performs all necessary simulations and calculations in advance during system setup or offline preparation, storing the results in lookup tables. When the system needs to select an RV during actual data transmission, it simply queries the pre-computed lookup table based on current MCS and re-transmission count, obtaining the optimal RV instantaneously without any simulation time consumption, thus maintaining maximum throughput while eliminating time delays
3Adaptability or versatility
If the specification or particulars of the system are changed, then new simulations must be performed, but this increases the workload and complexity
Solution Approach 1:
The patent structures the lookup tables to be parameter-driven, where the optimal RV selection depends on key system parameters such as MCS level and re-transmission count. When system specifications change, only the relevant parameter ranges or threshold values in the lookup tables need to be updated, rather than re-running complete simulations. This makes the system highly adaptable to specification changes while minimizing the effort required for reconfiguration
Data Source
AI summary
An apparatus and method for maximizing throughout for HARQ transmissions is provided. Systematic and prodeduralized RV selection is facilitated by determining the parameter “s” by using two important factors affecting the system throughout, specifically the coding gain varying according to the code rate and the balance between energy per systematic bit and energy per parity bit.