Qualcomm Interview Question Bank continued from Part 2…
Q : What is the difference between latch and flip-flop?
A : The main differences between latch and flip-flop can be understood here.
Q : What is the Nyquist rate condition and condition for no aliasing to take place?
A : If a signal is bandlimited to W Hz, it can be reconstructed from samples at the receiver if the sampling rate is greater than or equal to 2W. To avoid aliasing, the sampling rate should always be greater than 2W because at the boundary case (i.e. sampling rate = 2W) also there is a possibility of aliasing to occur.
Q : Write the expression for reconstruction of a sampled signal?
A : The process of reconstructing the original signal from the samples received at the receiver is called as interpolation. If the signal is represented by x(t), the reconstructed signal, after some mathematical manipulation, can be represented by the following expression,
Reconstruction of a sampled signal
The terms are simply the multiplication of each sinc function by its corresponding sample value and then adding all the scaled and shifted sinc functions i.e. the reconstructed (interpolated) value at any point is obtained by adding the contributions from infinitely many weighted sinc functions.
Q : How do you define selectivity in a radio receiver?
A : Selectivity is defined as the ability to select the required band of frequencies and reject the unwanted ones.
Q : Draw a circuit for a set of logic equations using PLA.
A : The step-by-step process for drawing the circuit can be understood here.
Q : What is the purpose of using a tuned circuit between stages in the radio receiver?
A : The main purpose is to increase the sensitivity and selectivity of the radio receiver.
Q : What is pipelining?
A : Pipelining is the process of en-queuing the next process to be executed while the current process is still under execution.
(Continued to Part 4…)
Gautam Vashisht