## 11. During transmission over a communication channel, bit errors occur independently with probability p. If a block of n bits is transmitted, the probability of at most one bit error is equal to

## 12. A signal having uniformly distributed amplitude in the interval (-V to + V), is to be encoded using PCM with uniform quantization. The signal to quantizing noise ratio is determined by the

## 13. Companding in PCM systems lead to improved signal to quantization noise ratio. This improvement is for

## 14. In binary data transmission DPSK is preferred to PSK because

## 15. Consider a binary digital communication system with equally likely 0's and 1's. When binary 0 is transmitted the detector input can lie between the levels -0.25V and +0.25V with equal probability: when binary 1 is transmitted, the voltage at the detector can have any value between 0 and 1 V with equal probability. If the detector has a threshold of 0.2 V (i.e., if the received signal is greater than 0.2 V, the bit is taken as 1), the average bit error probability is

## 16. A source produces binary data at the rate of 10 kbps. The binary symbols are represented as shown in the figure.

The source output is transmitted using two modulation schemes, namely Binary PSK (BPSK) and Quadrature PSK (QPSK). Let and B2 be the bandwidth requirements of BPSK and QPSK respectively. Assuming that the bandwidth of the above rectangular pulses is 10 kHz, B_{1} and B_{2} are

The source output is transmitted using two modulation schemes, namely Binary PSK (BPSK) and Quadrature PSK (QPSK). Let and B2 be the bandwidth requirements of BPSK and QPSK respectively. Assuming that the bandwidth of the above rectangular pulses is 10 kHz, B

_{1}and B

_{2}are