In the output of a DM speech encoder, the consecutive pulses are of opposite polarity during time interval t₁ $$ \le $$ t $$ \le $$ t₂. This indicates that during this interval

For a bit-rate of 8 kbps, the best possible values of the transmitted frequencies in a coherent binary FSK system are

A band limited signal is sampled at the Nyquist rate. The signal can be recovered by passing the samples through

Quadrature multiplexing is