16-QAM
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From: jimmy1 on 17 Feb 2010 08:59 Hi everyone, I have a question, A maximum transmission vector in 16-QAM constellation is 100 volts rms. I have to determine the long-term average power transmitted from a 50 ohm antenna if each point in the constellation is equally likely to be transmitted. Any ideas? Thank you Jimmy
From: dvsarwate on 17 Feb 2010 09:27 On Feb 17, 7:59 am, "jimmy1" <testbe...(a)yahoo.com> wrote: > Hi everyone, > I have a question, A maximum transmission vector in 16-QAM constellation > is 100 volts rms. I have to determine the long-term average power > transmitted from a 50 ohm antenna if each point in the constellation is > equally likely to be transmitted. Any ideas? > > Thank you > > Jimmy Homework?
From: Clay on 17 Feb 2010 10:29 On Feb 17, 8:59 am, "jimmy1" <testbe...(a)yahoo.com> wrote: > Hi everyone, > I have a question, A maximum transmission vector in 16-QAM constellation > is 100 volts rms. I have to determine the long-term average power > transmitted from a 50 ohm antenna if each point in the constellation is > equally likely to be transmitted. Any ideas? > > Thank you > > Jimmy Here's a hint (in case this is homework)/ Figure out the power associated with each of the 16 states. Also figure out the probability of occurance of each state and then find the sum of the product of probability and power for all states. IHTH, Clay
From: Jerry Avins on 17 Feb 2010 10:56 Clay wrote: > On Feb 17, 8:59 am, "jimmy1" <testbe...(a)yahoo.com> wrote: >> Hi everyone, >> I have a question, A maximum transmission vector in 16-QAM constellation >> is 100 volts rms. I have to determine the long-term average power >> transmitted from a 50 ohm antenna if each point in the constellation is >> equally likely to be transmitted. Any ideas? >> >> Thank you >> >> Jimmy > > Here's a hint (in case this is homework)/ Figure out the power > associated with each of the 16 states. Also figure out the probability > of occurance of each state and then find the sum of the product of > probability and power for all states. jimmy1, See if you can explain to yourself how the antenna's impedance influences the result. Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
From: Eric Jacobsen on 17 Feb 2010 13:02
On 2/17/2010 7:27 AM, dvsarwate wrote: > On Feb 17, 7:59 am, "jimmy1"<testbe...(a)yahoo.com> wrote: >> Hi everyone, >> I have a question, A maximum transmission vector in 16-QAM constellation >> is 100 volts rms. I have to determine the long-term average power >> transmitted from a 50 ohm antenna if each point in the constellation is >> equally likely to be transmitted. Any ideas? >> >> Thank you >> >> Jimmy > > Homework? That is a pretty good h/w question, though. One should have a good idea of how that part of the system works after sorting that out. -- Eric Jacobsen Minister of Algorithms Abineau Communications http://www.abineau.com |