The output S/N at thereceiver must be greater than 40 dB. The audio signal has zero mean, maximum amplitude of 1, power of ½ Wand bandwidth of 15 kHz. The power spectral density of white noise N0/2 = 10-10W/Hz and the power loss in the channel is 50 dB. Determine the transmit power required and the bandwidth needed.

Given that,

The output signal at the receiver must be greater than 40 dB.

Maximum amplitude = 1

Bandwidth = 15 kHz

The power spectral density of white noise is

Power loss in channel= 50 dB

Suppose, Using DSB modulation

We need to calculate the power required

Using formula of power

Put the value into the formula

For DSB modulation,

Figure of merit = 1

We need to calculate the input signal

Using formula of FOM

Put the value into the formula

We need to calculate the transmit power

Using formula of power transmit

Put the value into the formula

We need to calculate the needed bandwidth

Using formula of bandwidth for DSB modulation

Put the value into the formula

Hence, The transmit power is 3 kW.

The needed bandwidth is 30 kHz.