As A Conventional Road Test Appearance, The Digital Scanner Truly Reflects The Wireless Environment Of The Test Area. It Is Used In CW (Continuous Wave) Signal Testing, Network Optimization Road Testing, And Network Optimization Work For Room Distribution Systems.
Let’s Take A Look At The Common Parameters And Principles Of The Time And Division Of The Digital Scanner To Disturb The Investigation.
The Important Parameters Of The Digital Scanner Include Internal Attenuator Settings, RBW (Resolution Bandwidth) Settings, Frequency Band Size Settings, Etc.
The Principle Of Internal RF Attenuator Setting Is:
(1) When It Is Necessary To Search For Small Signals, The Attenuation Value Should Be Set As Low As Possible, Otherwise The Searched Target Signal Will Be Swallowed By The Bottom Noise Of The Frequency Scanner And Cannot Be Seen;
(2) When It Is Necessary To Detect Strong Signals, The Attenuation Value Should Be Set As High As Possible, Otherwise It Will Cause Nonlinear Distortion In The Circuit Of The Scanner, Display False Signals, And Even Damage The Appearance;
The RBW Setting Principles Are:
(1) When Searching For Small Narrowband Signals, The RBW Value Should Be Set As Low As Possible, Otherwise The Search Target Signal Will Be Merged And Cannot Be Distinguished, And Even Be Swallowed By The Noise Of The Scanner And Completely Invisible; But If If The RBW Value Is Too Low, The Sweep Time Will Be Too Long And The Test Power Will Be Affected;
(2) Considering That The Bandwidth Of A Single RB Of GSM Signal, PHS Signal And TD-LTE Is Close To 200K, And Overall Testing Power, It Is Recommended That The RBW Of The Scanner Be Set To 200KHz.
The Frequency Band Size Setting Principle Is:
(1) Through Filter Cooperation, Set The Frequency Band Scale To The LTE System Bandwidth Scale To Investigate In-Band Interference Conditions, Such As F-Band TDS In-Band Interference, GSM Second Harmonic Interference, And DCS Intermodulation Interference. It Is Advisable To Connect The Corresponding Frequency Band Filter When Sweeping The Frequency. For Example, The F-Band Scrambling Investigation Is Set To 1880-1900MHz. When Sweeping The Frequency, Any Port Of The Antenna Can Be Disconnected At The RRU, Connecting The Filter, And Connecting The Filter Output Port With The Frequency Scanner;
(2) Sweep The Upper And Lower Adjacent Frequency Bands Of The Target Frequency Band To Investigate Whether There Are Different System Signal Occupations On Different Sub-Bands. For Example, When Investigating The Interference Of F-Band, You Can Set The Sweep Frequency Band Scale 1805MHz-1920MHz, And Investigate 1805-1920MHz Separately. According To The Signal And Intensity Of 1830MHz, 1830-1850MHz, 1850-1880MHz, And 1900-1920MHz Frequency Bands, Investigate The Signal Strength Of DCS According To The Interference Waveform To Help Determine Whether There May Be DCS Spurious And Full Interference;
Combining The In-Band Interference Conditions And The Out-Of-Band Interference Conditions Of The Upper And Lower Adjacent Frequencies In The Above Two Steps, It Is Possible To Analyze Various Interference Weights In A Chaotic Scene Where Multiple Interferences Are Superposed.
Post time: Feb-06-2021
