Single-Antenna TDD Spectrum Analyzer for UL/DL Synchronization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional RF spectrum analyzers for TDD networks require Global Navigation Satellite System (GNSS) receivers for synchronization, leading to higher costs and reduced battery life, and struggle with maintaining synchronization over extended periods during interferer hunting.
Innovation Solution
An RF spectrum analyzer that maintains synchronization between uplink and downlink using a single antenna by combining spectrum and signal analyzer modes to extract radio frame synchronization, allowing internal oscillator discipline and alternating sample acquisition between sync and analysis regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a GNSS receiver is used for synchronization in the RF spectrum analyzer, then time synchronization with the base station is achieved, but the device complexity and cost increase
Solution Approach 1:
The patent extracts the synchronization function from the GNSS receiver and implements it using the existing single antenna and internal oscillator. The RF spectrum analyzer captures radio frames through the single antenna, extracts synchronization signals (PSS/SSS) from the captured frames, and uses these to discipline the internal oscillator, thereby achieving time synchronization without requiring a GNSS receiver.
Solution Approach 2:
The system uses itself to achieve synchronization - the same single antenna that captures the signal for analysis is also used to capture the synchronization signals. The internal oscillator disciplines itself using the synchronization signals extracted from the captured radio frames, eliminating the need for external synchronization hardware.
2Reliability
If a GNSS receiver is used for synchronization, then accurate time reference is obtained, but power consumption increases and battery life decreases
Solution Approach 1:
The synchronization function is extracted from the power-consuming GNSS receiver and implemented using the existing single antenna and internal oscillator. The system captures radio frames through the single antenna, extracts synchronization signals, and disciplines the internal oscillator without requiring continuous GNSS signal processing, significantly reducing power consumption.
Solution Approach 2:
Instead of continuous synchronization signal processing required by GNSS receivers, the system periodically captures radio frames and extracts synchronization signals at specific intervals. The internal oscillator runs freely between synchronization events and is disciplined periodically, reducing the average power consumption while maintaining synchronization accuracy.
3Ease of operation
If manual gating of UL and DL slots is performed with a free running timebase, then operation is simple, but the gating slips over time requiring frequent readjustment
Solution Approach 1:
The system implements a feedback mechanism where the internal oscillator is continuously disciplined using synchronization signals extracted from captured radio frames. The phase and frequency of the internal oscillator are adjusted based on the extracted synchronization signals, creating a closed-loop system that maintains accurate timing without manual intervention. This feedback mechanism prevents the gating from slipping over time while maintaining ease of operation.
Solution Approach 2:
The system automatically maintains synchronization without manual readjustment by using the extracted synchronization signals to discipline the internal oscillator. The automatic timing alignment eliminates the need for technicians to manually readjust gating parameters during interferer hunting operations, maintaining both ease of operation and synchronization stability.
4Reliability
If multiple antennas are used for synchronization and analysis, then synchronization accuracy is improved, but cost and power consumption increase
Solution Approach 1:
The single antenna is designed to perform multiple functions: it captures both the synchronization signals (PSS/SSS) and the radio frames for spectrum analysis. The same antenna signal path is used for both synchronization extraction and interferer detection, eliminating the need for separate antennas while maintaining synchronization accuracy and reducing device complexity.
Solution Approach 2:
The patent merges the synchronization function and the spectrum analysis function into a single integrated process using one antenna. The captured signal is processed to extract synchronization signals for timing reference, and the same captured signal is also used for spectrum analysis and interferer detection, combining multiple functions into a unified system that reduces hardware requirements.
Data Source
AI summary
A Radio Frequency (RF) spectrum analyzer includes an RF front end including a single antenna configured to monitor a wireless network that includes Time Division Duplexing (TDD); and circuitry connected to the RF front end and configured to operate and monitor the wireless network both in a spectrum analyzer mode and a signal analyzer mode, utilize the signal analyzer mode to extract synchronization information from the monitored wireless network, derive a start of frame of a radio frame from said the synchronization information; and utilize the synchronization information to identify an acquisition window to synchronize a gate in the spectrum analyzer mode.