Noise in SSB Systems

Single sideband (SSB) systems are also susceptible to various types of noise that can degrade the quality of the received signal. The most common types of noise in SSB systems are thermal noise, phase noise, and adjacent channel interference.

1. Thermal noise: As mentioned earlier, thermal noise is generated by the random motion of electrons in a conductor at a finite temperature. In SSB systems, thermal noise is present in the receiver components such as amplifiers and mixers, and it can degrade the quality of the received signal.

 2. Phase noise: Phase noise is a type of noise that is present in oscillators and can cause fluctuations in the phase of the carrier signal. In SSB systems, phase noise can cause distortion in the received signal, especially if the receiver is sensitive to phase noise.

3. Adjacent channel interference: Adjacent channel interference is caused by signals from nearby channels that leak into the desired channel. In SSB systems, adjacent channel interference can be caused by imperfect filtering and can cause distortion in the received signal.

To minimize the effect of noise and interference in SSB systems, various techniques such as filtering, equalization, and modulation schemes can be used. For example, using high-Q filters can help minimize the effect of adjacent channel interference by rejecting unwanted signals. Using a high-quality oscillator with low phase noise can help minimize the effect of phase noise. Additionally, using a carrier recovery circuit with a wide capture range can help extract the carrier signal and improve the receiver's overall performance. 

Let SSB modulated signal is
u(t)=𝐴𝑐𝑚(𝑡) cos(2𝜋𝑓 𝑐t)±𝑚 ̂(t) sin (2𝜋𝑓 𝑐t)
Input to the demodulator