13k views

What is an Intuitive Explanation of the Phase of a Signal

I understand that the meaning of the phase response of a system is simply how much the system delays a frequency component. However, I do not find an intuitive explanation for the phase of a signal. ...
1k views

Recovering signal for psk

I am currently working on a product(cant disclose too much details of the actual project) in which some data is being sent via audible(but on the higher freq) sound that is encoded with dqpsk. ...
2k views

baseband and passband modulation

I have a simulink model over 2.4GHz. In the transmitter part, the modulation is O-QPSK modulated baseband instead of passband modulation. In Matlab Help this is the reason of using baseband ...
726 views

I've a Gaussian modulated signal whose quadrature and in phase components are separated. I'm multiplying these components with quadrature and in phase components of a signal of 10MHz frequency, ...
521 views

Understanding I and Q modulation

As a newbie I am trying to understand I and Q modulation and demodulation. So from what I read the I and Q components of a signal separately mix with RF signals that are 90 degrees out of phase with ...
129 views

Why Shannon Theorem has nothing to do with frequency?

According to Shannon theorem $$C= B \log _2(1 + S/N)$$ My question is, why there is no frequency in this formula? Let's say we have 2 channels, both of them have same 20 MHz bandwidth, one is from ...
315 views

Software PLL tracking of carrier frequency in bandlimited transmission

My understanding is that a PLL(either in hardware or software) can recover the carrier frequency(or be used to correct the frequency offset) of a system. My question is how does this work when the ...
164 views

Effects of interchanging sine terms with cosine terms

Suppose we have a real signal $x(t)$. Now, we know that $x(t)$ can be represented as a sum of sines and cosines. w be the angular frequency. If $a(\omega)$ be the coefficients of the cosine terms, ...
71 views

Level Correction For Digital Down-Convertion?

I am trying to understand a subtle (sorry if this is obvious) difference in the computed output power after a DDC process. Here is the story: Suppose I generated a 10 MHz signal from a microwave ...
88 views

Complex filters used in analog domain [closed]

Complex filters can be used in low IF architecture especially in DSP in order to phase out (reject) the image signal. How are complex filters implemented in the analog domain?
When using for example, polar signaling of full width rectangular pulses, the bandwidth is equal to the pulse rate $Rb$, which is also the bit rate. $B=R_b$ for full width rectangular pulses. But ...