*Question E8A07:
What determines the PEP-to-average power ratio of an unprocessed single-sideband phone signal?*  

*Correct Answer is  B: Speech characteristics*  

### AI Response: (may contain errors)  

The PEP-to-average power ratio of an unprocessed single-sideband (SSB) phone signal is determined by the speech characteristics. Here's why:

1. **Correct Answer: Speech characteristics (B)**
   - The PEP (Peak Envelope Power) of an SSB signal is influenced by the peaks in the speech waveform. Speech is inherently variable, with peaks and troughs that affect the power levels. The ratio of these peaks to the average power is determined by the dynamic range and modulation characteristics of the speech itself.

2. **Why the other choices are incorrect:**
   - **The frequency of the modulating signal (A):** While the frequency of the modulating signal affects the bandwidth of the SSB signal, it does not directly influence the PEP-to-average power ratio. This ratio is more about amplitude variations rather than frequency.
   - **The degree of carrier suppression (C):** In SSB, the carrier is suppressed to reduce power consumption and bandwidth. However, carrier suppression does not affect the PEP-to-average power ratio, as this ratio is concerned with the modulated signal's envelope, not the carrier.
   - **Amplifier gain (D):** Amplifier gain affects the overall power level of the signal but does not change the ratio between peak and average power. The PEP-to-average power ratio is a characteristic of the signal itself, not the amplification process.

In summary, the PEP-to-average power ratio is primarily a function of the speech waveform's characteristics, which include its dynamic range and modulation depth.