PART A
INTRODUCTION
A sideband is a type of band in the field of radio communication systems. There are two types of bands called upper sideband (USB) and lower sideband (LSB). The upper sideband is located above the carrier frequency while the lower sideband (LSB) is located below the carrier frequency. Carrier frequency contains the power by the process called Amplitude modulation (AM).
There are two types of sideband modulation signal :
1) SINGLE-SIDEBAND SIGNAL (SSB)
Single-sideband is a very easy way to transmit voice, audio or other information on a radio wave. The method where the audio is impressed on a radio wave signal is defined ad modulation. There are two types of modulation ; AM ( Amplitude modulation ) and FM (Frequency modulation ) . In an AM-modulated signal, the base signal or more oftenly called the carrier will be continuously transmitted. There will be two signal that are idendical called the sideband modulating signals will be attached to the carrier wave in opposite manner. The sideband above the carrier wave is referred upper sideband (USB) while the sideband while located below the carrier wave is called lower sideband (LSB). SSB signal is produced by removing one of the sidebands either the upper sideband , the sideband with the higher frequency or the lower sideband, the sideband with the lower frequency.Most oftenly, the carrier is removed (suppressed) being defined as single-sideband suppressed carrier (SSBSC). The filteration of one of the sideband can be done by inserting a special component called band filter. This removal of one of the sideband will not affect the audio that to be transmitted because the upper sideband and lower sideband were actually identical. If we listen to an SSB signa...
... middle of paper ...
...r force’s Strategic Air Command to make sure a reliable communication between the NORAD and the nuclear bombers. SSB was the only communication with the bombers before using the satellite communication.
APPLICATIONS OF DOUBLE-SIDEBAND SIGNAL
- point to point communication
= Almost all of the point to point circuits that connects the naval communication stations will use the provided frequency spectrum of double-sideband. DSB used in naval communication to expand the traffic capability. Basically, DSB takes the output from two sideband generators. It remove the upper sideband from one and the lower sideband from the other one and combine them to transmit.
- air traffic control radius
= The air traffic control that are currently being used is VHF radio. This system uses double-sideband transmitted carrier (DSBTC) analog modulation to make the voice transmission.