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electronics_sky
Joined: 09 Feb 2006
Posts: 49
Helped: 1
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 18 Mar 2006 17:47 SINGLE CHANNEL QPSK?? |
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hi there,
I am doing an asignment regarding using HDL to build a QPSK modulator.
I only knew that psk is differentiate from how many phases is using but i have no idea how it can it differentiate by using channel.
1. Can i know what it means by single channel QPSK modulator?DOes it refer to how many bit is the input signal?
2. What is look-up table? How can it be used to do pulse shapping when i wrote my code in VHDL?
3.Why qpsk modulator only have a single bit polar NRZ input? I am wondering why it is not higher bits(eg. 8bit), because the input represent the sample signal from an ADC.
4.What is it refer to when we said about phase constellation of pi/4,3pi/4,-3pi/4,-pi/4 for QPSK modulator?
5.as we know that QPSK modulator transmit data twice as fast as BPSK does, but how is it when compare to pi/4 QPSK modulator?
thank you in advance.
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rextor
Joined: 19 Mar 2006
Posts: 40
Helped: 7
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| 19 Mar 2006 20:00 Re: SINGLE CHANNEL QPSK?? |
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check this ref. if could help u....
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rextor
Joined: 19 Mar 2006
Posts: 40
Helped: 7
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| 19 Mar 2006 20:08 Re: SINGLE CHANNEL QPSK?? |
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QPSK Modem Reference Design
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rextor
Joined: 19 Mar 2006
Posts: 40
Helped: 7
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| 19 Mar 2006 20:15 Re: SINGLE CHANNEL QPSK?? |
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Hierarchical Modulation - the transmission of two independent DVB-T multiplexes on a single frequency
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rextor
Joined: 19 Mar 2006
Posts: 40
Helped: 7
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| 19 Mar 2006 20:19 Re: SINGLE CHANNEL QPSK?? |
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CDMA Technology
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