RF spectrum analyzer for TDD transmission that maintains synchronization between UL and DL with a single antenna

Patent metadata

Field	Value
Publication number	US-12520253-B2
Application number	US-202218087276-A
Country	US
Kind code	B2
Filing date	Dec 22, 2022
Priority date	Dec 22, 2021
Publication date	Jan 6, 2026
Grant date	Jan 6, 2026

Abstract

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.

First claim

What is claimed is:

1 . A Radio Frequency (RF) spectrum analyzer comprising:
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 the synchronization information; and
utilize the synchronization information to synchronize a gate in the spectrum analyzer mode,
wherein, (i) when a frequency of any of primary synchronization signal (PSS) and secondary synchronization signal (SSS) are at same frequencies as an analysis region, the RF font end is tuned to a single frequency within a range of the analysis region for spectrum analysis, or (ii) when the frequency of any of the PSS and the SSS are not within an analysis region, the circuitry concurrently operates by alternating sample acquisition between a synchronization location and the analysis region, the recover the frequency of any of the PSS and the SSS.

2 . The RF spectrum analyzer of claim 1 , wherein the synchronization information includes any of frequency synchronization and radio frame synchronization.

3 . The RF spectrum analyzer of claim 1 , wherein the circuitry includes a free running timebase that is periodically updated based on the synchronization information.

4 . The RF spectrum analyzer of claim 1 , wherein the synchronization information is used to establish a precise timebase and/or to extend a time between synchronization of the timebase.

5 . The RF spectrum analyzer of claim 1 , wherein the single antenna is configured to monitor one of uplink and downlink slots based on configuration from the synchronization information.

6 . The RF spectrum analyzer of claim 1 , wherein, when the frequency of the any of PSS and the SSS are in an analysis region, but not exactly at a center frequency of the analysis region, the circuitry is configured to recover the frequency of the any of the PSS and the SSS is using one of a digital up converter and a digital down converter.

7 . The RF spectrum analyzer of claim 1 , wherein the wireless network includes any of 5G and Long Term Evolution (LTE).

8 . The RF spectrum analyzer of claim 1 , wherein the synchronization information is from a different standard than the spectrum analyzer mode operates.

9 . The RF spectrum analyzer of claim 1 , wherein the circuitry is further configured to hunting for interferences in an uplink (UL) reserved slot of the TDD.

10 . A method implemented in a Radio Frequency (RF) spectrum analyzer with an RF front end including a single antenna configured to monitor a wireless network that includes Time Division Duplexing (TDD), the method comprising steps of:
operating and monitoring the wireless network both in a spectrum analyzer mode and a signal analyzer mode; utilizing the signal analyzer mode to extract synchronization information from the monitored wireless network; deriving a synchronization of frame of a radio frame from the synchronization information; utilizing the extracted information to synchronize a gate in the spectrum analyzer mode; and one of (i) recovering the frequency of any of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) using one of digital up converting and digital down converting, when a frequency of the any of the PSS and the SSS are at same frequencies as an analysis region, and an RF font end is tuned to a single frequency within a range of the analysis region for spectrum analysis, or (ii) alternating sample acquisition between a synchronization location and the analysis region, for recovering the frequency of any of the PSS and the SSS, when the frequency of any of the PSS and the SSS are not within the analysis region.

11 . The method of claim 10 , wherein the synchronization information includes any of frequency synchronization and radio frame synchronization.

12 . The method of claim 10 , wherein the steps further include utilizing a free running timebase that is periodically updated based on the synchronization information.

13 . The method of claim 10 , wherein the synchronization information is used to establish a precise timebase and/or to extend a time between synchronization of the timebase.

14 . The method of claim 10 , wherein the single antenna is configured to monitor uplink and downlink slots based on configuration from the synchronization information.

15 . The method of claim 10 , wherein the synchronization information is from a different standard than the spectrum analyzer mode operates.

16 . The method of claim 10 , wherein the steps further include
hunting for interferences in an uplink (UL) reserved slot of the TDD.

Assignees

• Exfo Inc

Inventors

• Lapierre Dominic
• Germain Luc

Classifications

• H04W24/08

  Testing, {supervising or monitoring} using real traffic · CPC title

• H04L5/14

  Two-way operation using the same type of signal, i.e. duplex · CPC title

• H04B17/345

  Interference values ({signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR]} H04B17/336) · CPC title

• H04W56/001 Primary

  Synchronization between nodes · CPC title

• H04L27/2675 Primary

  Pilot or known symbols · CPC title