about dpsk!
时间：04-12
整理：3721RD
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From abundent material about psk,i konw there are following demodulating method:
1. differential method: it is the most easy to demodulate the signal,just need to mutiply two successive codes, however the delay time is critcal.
2.generate an carry wave using costas loop or other related circuit,then multiply the carry wave with the input signal,howver the costas is not easy to design even with some digital costas loop ASIC such as hsp 50210.
3.sotware demodulation: it is implement with some complicated algorithm in dsp eviroment.
if i am wrong ,plz correct me, thanks a lot.
does anyone know the demodulations of psk or dpsk or qpsk or 8psk,which way do u think is the easy and best to implement it.
1. differential method: it is the most easy to demodulate the signal,just need to mutiply two successive codes, however the delay time is critcal.
2.generate an carry wave using costas loop or other related circuit,then multiply the carry wave with the input signal,howver the costas is not easy to design even with some digital costas loop ASIC such as hsp 50210.
3.sotware demodulation: it is implement with some complicated algorithm in dsp eviroment.
if i am wrong ,plz correct me, thanks a lot.
does anyone know the demodulations of psk or dpsk or qpsk or 8psk,which way do u think is the easy and best to implement it.
The Costas loop is an optimum solution. All methods will have the 180 degree phase ambiguity. There are two ways around this. One is to have a known preamble. The other is the differential way which will produce twice the BER because one received bit error will affect two data bits.