Time Shared Rake Fingers for Reduced IC Die Area
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Solution Overview
Problem
Existing rake receivers in CDMA radio telecommunications systems require significant space on integrated circuit dies due to the separate instantiation of multiple fingers and path searchers, which complicates timing adjustments and increases power consumption, especially in environments with multi-path propagation.
Innovation Solution
A time multiplexed rake receiver architecture that allows a single physical finger to operate as multiple virtual fingers, with a buffer and spare processing slots, enabling efficient timing adjustments and reduced hardware requirements, while also allowing the path searcher to operate in a time multiplexed manner, thereby reducing the overall silicon footprint and improving power efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple fingers and path searchers are separately instantiated in a rake receiver, then the receiver can handle multi-path propagation effectively, but the space required on integrated circuit dies increases significantly
Solution Approach 1:
The patent merges multiple separate fingers into a single time-shared finger that can be dynamically allocated to different time slots. Instead of having multiple parallel finger structures occupying separate circuit space, one physical finger is shared across multiple virtual fingers through time multiplexing, significantly reducing the integrated circuit area while maintaining the capability to handle multiple propagation paths
Solution Approach 2:
The single time-shared finger is designed to perform multiple functions by being allocated to different virtual fingers at different time slots. This universal structure can serve as any of the multiple fingers depending on the current time slot assignment, enabling one component to replace multiple specialized components and thereby reducing overall circuit complexity and area
2Ease of operation
If multiple separate fingers are instantiated, then timing adjustments can be made for each path, but the device complexity and power consumption increase
Solution Approach 1:
The patent introduces dynamic time slot allocation where a single finger is dynamically assigned to different virtual fingers based on current processing needs. This dynamic sharing allows timing adjustments to be made for different propagation paths by allocating the shared finger to appropriate virtual fingers at different time slots, maintaining timing flexibility while reducing the number of permanent structural components
Solution Approach 2:
The time-shared finger operates in periodic time slots, cycling through different virtual finger assignments. This periodic operation allows the same physical finger to serve multiple functions sequentially, reducing device complexity by eliminating the need for multiple simultaneous finger structures while maintaining the ability to perform timing adjustments for different paths during their respective time slots
3Measurement precision
If multiple path searchers are separately implemented, then path detection accuracy is improved, but the silicon footprint and power consumption increase
Solution Approach 1:
The patent merges multiple separate path searchers into a single time-shared path searcher that operates in different time slots to perform path detection for multiple virtual fingers. This consolidation reduces the number of active path searcher components from multiple to one, thereby reducing power consumption while maintaining path detection accuracy through sequential operation across different time periods
Data Source
AI summary
A rake receiver having a rake receiver finger operated in a time multiplexed manner to perform the task a plurality of fingers, each of these fingers being a virtual finger allocated to a time slot in an operation cycle of the rake receiver finger, and wherein a buffer is provided for buffering at least one received chip of data, and where a spare virtual finger is provided such that any virtual finger may request extra processing within an operation cycle of the time multiplexed rake receiver finger.