Introduction

In this lab session we are going to study the SSBSC modulation and demodulation. The SSBSC is a shortage for Single Sideband Suppressed Carrier. It transmits only a one sideband, so that it cannot transmit both of the sum and the difference of frequencies. One advantage of the SSBSC is that it requires only half the bandwidth of the DSBC and AM.

Equipment * Emona Telecom-Trainer 101 * Dual Channel 20MHz oscilloscope * Two Emona Telecom-Trainer 101 oscilloscope leads * Assorted Emona Telecom-Trainer 101 Patch Leads

Procedure

Part a: Generating an SSBSC signal using a simple message

We start by doing the connection by the following steps: * First, we make sure that the Trigger Source control is set to the CH 1 position. * Then we set the scope mode control to the DUAL position. * We insert the black plugs of the Oscilloscope into a ground, and we followed the schematic shown in Figure 1 to implement the connection shown in figure 2.

Figure [ 1 ]

Figure [ 2 ] First implementation

* Later we adjust the scope's Time base control to view two or more cycles of the two message signals. * We set the phase shifter module's Phase Change control to the 180° position, and we set the Phase Adjust to the middle of its travel. * We followed the schematic shown in Figure 3 to do the implementation shown in Figure 4.

Figure [ 3 ]

Figure [ 4 ]

* We used the scope to check that the lower Multiplier module's output is a DSBC signal. * Then we disconnected channel 2 input from the lower Multiplier module's output and connect it to its upper module. And we check that its outputting a DSBC signal. * After that we locate the Adder module and set its G and g controls to the middle of its travel.

Results and Discussion
In this part of the lab report we are going to analyze and discuss the results. For the first connection done in the lab we received the following output signal shown in figure 5. We can see that we have set up two message signals that are out of phase it each other.

Figure [ 5 ]

For the second connection done in part 1, we received the following output signal shown in Figure 6. the two message signal is multiplied with two 100KHz sine waves that are exactly 90° out of the phase with each other. As the output of the multiplier should be a DSBC signal.

Figure [ 6 ]

Answers for the questions: 1. Though we get a SSB signal, we won't be able to guess which sideband is used in which that both of the bands are consist of the information. Also the phase shifter might not be 90 degrees.

Conclusion
To conclude, we performed the SSBSC modulation and demodulation using the EMONA Telecom-Trainer 10. The aim of the lab was to make us able to generate an SSBSC signal using sine wave, by implementing the mathematical model for the phasing method. We will find that the two DSBC signals will be produced and sent through a multiplier. Then we will receive the SSBSC signal as an output from the adder.