Preamble Detection in 4G LTE Base Stations
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Solution Overview
Problem
Current 4G LTE/5G base station receivers require multiple preamble detectors running simultaneously at each carrier frequency for efficient preamble detection, leading to high memory usage and inefficiencies in processing uplink transmissions with varying sample rates and bandwidths.
Innovation Solution
A method and apparatus that involve frequency shifting, oversampling, and downsampling of preamble data using a processor and memory to generate frequency shifted and preamble samples, with parameter updates, allowing for efficient detection of preambles with reduced memory requirements and hardware reuse.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple preamble detectors are run simultaneously at each carrier frequency, then preamble detection accuracy is improved, but memory usage increases
Solution Approach 1:
The patent merges multiple preamble detector instances into a single detector that processes multiple carrier frequencies sequentially. The same hardware detector is reused across different frequencies by loading appropriate parameters (preamble sequences, frequency offsets, bandwidth settings) from a parameter database, eliminating the need for multiple simultaneous detector instances and reducing memory requirements.
Solution Approach 2:
The patent creates a universal preamble detector that can function across multiple carrier frequencies and handle different preamble formats. By making the detector configurable through parameter loading from a database, a single detector instance performs the work of multiple dedicated detectors, optimizing resource utilization while maintaining detection accuracy.
2Adaptability or versatility
If multiple preamble detectors are run simultaneously at each carrier frequency, then preamble detection coverage is improved, but device complexity increases
Solution Approach 1:
The patent implements a universal detector design that can adapt to different carrier frequencies and preamble formats through parameter configuration rather than hardware duplication. This single multi-functional detector maintains comprehensive detection coverage while avoiding the complexity of multiple simultaneous detector instances.
Solution Approach 2:
The patent introduces dynamic parameter loading where the detector's operating parameters (frequency offsets, preamble sequences, bandwidth) are loaded from a database based on the current carrier frequency being processed. This dynamic reconfiguration allows one detector to adapt to multiple scenarios without requiring static hardware for each frequency.
3Quantity of substance
If frequency shifting and downsampling operations are performed, then memory usage is reduced, but processing time increases
Solution Approach 1:
The patent performs frequency shifting and downsampling operations as preliminary processing steps before the main correlation-based preamble detection. By pre-processing the received signal to convert it to baseband and reduce the sampling rate, the subsequent detection algorithm operates on smaller data sets, reducing the overall processing time despite the added preprocessing steps.
Data Source
AI summary
Methods and apparatus for preamble detection in a communication network are disclosed. In an exemplary embodiment, a method includes retrieving parameters from a parameter database, filling a buffer of preamble data received in an uplink transmission from user equipment, and frequency shifting the buffer of preamble data based on one or more first parameters to generate frequency shifted data. The method also includes oversampling the frequency shifted data to generates oversampled data, downsampling the over sampled data based on one or more second parameters to generate preamble samples, and updating the parameter database with updated values for the one or more first and second parameters. The method also includes repeating all the operations until a selected amount of preamble samples is obtained.