# I/Q baseband Modulator Demodulator

1. ## I/Q baseband Modulator Demodulator

hi,

I want to understand I/Q modulation and demodulation process. I want to module a 10MHz bit stream (each bit has 100 nsec duration). Bit stream is in the form of 0 and 1. I want to perform BPSK.

How can i convert it to i/q base-band? What is the significance of I/Q modulation and demodulation?

Regards

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2. ## Re: I/Q baseband Modulator Demodulator

BPSK doesn't involve quadrature modulation, see https://en.wikipedia.org/wiki/Phase-shift_keying

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3. ## Re: I/Q baseband Modulator Demodulator

Originally Posted by adnan012
hi,

I want to understand I/Q modulation and demodulation process. I want to module a 10MHz bit stream (each bit has 100 nsec duration). Bit stream is in the form of 0 and 1. I want to perform BPSK.

How can i convert it to i/q base-band? What is the significance of I/Q modulation and demodulation?

Regards
this technique is quite popularly used in bandpass modulation in Digital communication, you need to take a look at "Digital Communication book" (maybe chapter 4) from Prof. SKLAR first, then go further to mod/demo circuit later

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4. ## Re: I/Q baseband Modulator Demodulator

Originally Posted by FvM
BPSK doesn't involve quadrature modulation, see https://en.wikipedia.org/wiki/Phase-shift_keying
In this case I/Q-modulation is overkill, but I think it can be used to create any modulation.
BPSK is easy to do, just set Q=0 and change I between +1 and -1 according to the data bits.
A more complex example is SSB, which is possible but not trivial to do with I/Q-modulation. The modulation signal must be transformed.

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