Hi Folks, I'm having an embarrassingly hard time deriving what should be a simple result in [proakiscomm]. Could someone please show me how he gets from equation 4.1-22 to 4.1-23? This is the equation for the energy in a bandpass signal. I don't see where the phi(t) comes from, for one thing. I have checked his errata at http://www.mhhe.com/engcs/electrical/proakis/errata.mhtml and find nothing referring to this equation. Any help would be appreciated. --Randy @BOOK{proakiscomm, title = "{Digital Communications}", author = "John~G.~Proakis", publisher = "McGraw-Hill", edition = "fourth", year = "2001"} -- % Randy Yates % "Remember the good old 1980's, when %% Fuquay-Varina, NC % things were so uncomplicated?" %%% 919-577-9882 % 'Ticket To The Moon' %%%% <yates@ieee.org> % *Time*, Electric Light Orchestra http://home.earthlink.net/~yatescr
Proakis Derivation
Started by ●December 10, 2006
Reply by ●December 10, 20062006-12-10
Randy Yates <yates@ieee.org> writes:> I don't see where the phi(t) comes from, for one thing.That should be "theta(t)," not phi(t). -- % Randy Yates % "Though you ride on the wheels of tomorrow, %% Fuquay-Varina, NC % you still wander the fields of your %%% 919-577-9882 % sorrow." %%%% <yates@ieee.org> % '21st Century Man', *Time*, ELO http://home.earthlink.net/~yatescr
Reply by ●December 10, 20062006-12-10
"Randy Yates" <yates@ieee.org> wrote in message news:m3bqmbqfot.fsf@ieee.org...> Randy Yates <yates@ieee.org> writes: > > > I don't see where the phi(t) comes from, for one thing.Now you know well we don't do homework's here. Have a go yourself or ask your Prof. Tam -- Posted via a free Usenet account from http://www.teranews.com
Reply by ●December 11, 20062006-12-11
Heid the baw - goal!! wrote:> "Randy Yates" <yates@ieee.org> wrote in message > news:m3bqmbqfot.fsf@ieee.org... >> Randy Yates <yates@ieee.org> writes: >> >>> I don't see where the phi(t) comes from, for one thing. > > Now you know well we don't do homework's here. Have a go yourself or ask > your Prof.Now tell me he's not a troll. :-( Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
Reply by ●December 11, 20062006-12-11
Jerry Avins <jya@ieee.org> writes:> Heid the baw - goal!! wrote: >> "Randy Yates" <yates@ieee.org> wrote in message >> news:m3bqmbqfot.fsf@ieee.org... >>> Randy Yates <yates@ieee.org> writes: >>> >>>> I don't see where the phi(t) comes from, for one thing. >> Now you know well we don't do homework's here. Have a go yourself or >> ask >> your Prof. > > Now tell me he's not a troll. :-(It is unfortunate that this newsgroup is denigrated by folks like this. Obviously if you think it's an illegitimate homework question you can simply choose not to respond. -- % Randy Yates % "The dreamer, the unwoken fool - %% Fuquay-Varina, NC % in dreams, no pain will kiss the brow..." %%% 919-577-9882 % %%%% <yates@ieee.org> % 'Eldorado Overture', *Eldorado*, ELO http://home.earthlink.net/~yatescr
Reply by ●December 11, 20062006-12-11
Randy Yates wrote:> Jerry Avins <jya@ieee.org> writes: > >> Heid the baw - goal!! wrote: >>> "Randy Yates" <yates@ieee.org> wrote in message >>> news:m3bqmbqfot.fsf@ieee.org... >>>> Randy Yates <yates@ieee.org> writes: >>>> >>>>> I don't see where the phi(t) comes from, for one thing. >>> Now you know well we don't do homework's here. Have a go yourself or >>> ask >>> your Prof. >> Now tell me he's not a troll. :-( > > It is unfortunate that this newsgroup is denigrated by folks like > this. Obviously if you think it's an illegitimate homework question > you can simply choose not to respond.Who, me? Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
Reply by ●December 11, 20062006-12-11
Jerry Avins <jya@ieee.org> writes:> Who, me?:) One's English is not what it is supposed to be... -- % Randy Yates % "Ticket to the moon, flight leaves here today %% Fuquay-Varina, NC % from Satellite 2" %%% 919-577-9882 % 'Ticket To The Moon' %%%% <yates@ieee.org> % *Time*, Electric Light Orchestra http://home.earthlink.net/~yatescr
Reply by ●December 11, 20062006-12-11
Randy Yates wrote:> Hi Folks, > > I'm having an embarrassingly hard time deriving what should be > a simple result in [proakiscomm]. Could someone please show me > how he gets from equation 4.1-22 to 4.1-23? This is the equation > for the energy in a bandpass signal. > > I don't see where the phi(t) comes from, for one thing. > > I have checked his errata at > > http://www.mhhe.com/engcs/electrical/proakis/errata.mhtml > > and find nothing referring to this equation. > > Any help would be appreciated. > > --Randy > > @BOOK{proakiscomm, > title = "{Digital Communications}", > author = "John~G.~Proakis", > publisher = "McGraw-Hill", > edition = "fourth", > year = "2001"} >I pulled out my handy copy of Proakis [really, I have one ;)] and if you jump back a page to 4.1.18 he expands s(t) to be equal to three representations, and I think you will find the answer there :) Cheers PeteS
Reply by ●December 11, 20062006-12-11
PeteS <peter.smith8380@ntlworld.com> writes:> Randy Yates wrote: >> Hi Folks, >> I'm having an embarrassingly hard time deriving what should be >> a simple result in [proakiscomm]. Could someone please show me >> how he gets from equation 4.1-22 to 4.1-23? This is the equation >> for the energy in a bandpass signal. I don't see where the phi(t) >> comes from, for one thing. I have checked his errata at >> http://www.mhhe.com/engcs/electrical/proakis/errata.mhtml >> and find nothing referring to this equation. >> Any help would be appreciated. >> --Randy >> @BOOK{proakiscomm, >> title = "{Digital Communications}", >> author = "John~G.~Proakis", >> publisher = "McGraw-Hill", >> edition = "fourth", >> year = "2001"} >> > > I pulled out my handy copy of Proakis [really, I have one ;)] and if > you jump back a page to 4.1.18 he expands s(t) to be equal to three > representations, and I think you will find the answer there :)Got it, Peter! Thanks for steering me straight. Man, that really threw me! Kept thinking theta(t) was a random phase and not part of the signal. -- % Randy Yates % "Bird, on the wing, %% Fuquay-Varina, NC % goes floating by %%% 919-577-9882 % but there's a teardrop in his eye..." %%%% <yates@ieee.org> % 'One Summer Dream', *Face The Music*, ELO http://home.earthlink.net/~yatescr
Reply by ●December 11, 20062006-12-11
Randy Yates wrote:> PeteS <peter.smith8380@ntlworld.com> writes: > >> Randy Yates wrote: >>> Hi Folks, >>> I'm having an embarrassingly hard time deriving what should be >>> a simple result in [proakiscomm]. Could someone please show me >>> how he gets from equation 4.1-22 to 4.1-23? This is the equation >>> for the energy in a bandpass signal. I don't see where the phi(t) >>> comes from, for one thing. I have checked his errata at >>> http://www.mhhe.com/engcs/electrical/proakis/errata.mhtml >>> and find nothing referring to this equation. >>> Any help would be appreciated. >>> --Randy >>> @BOOK{proakiscomm, >>> title = "{Digital Communications}", >>> author = "John~G.~Proakis", >>> publisher = "McGraw-Hill", >>> edition = "fourth", >>> year = "2001"} >>> >> I pulled out my handy copy of Proakis [really, I have one ;)] and if >> you jump back a page to 4.1.18 he expands s(t) to be equal to three >> representations, and I think you will find the answer there :) > > Got it, Peter! Thanks for steering me straight. Man, that really > threw me! Kept thinking theta(t) was a random phase and not part of > the signal.In years gone by I taught technically, so I am used to 'hunting down' the derivations. In this case, he substituted *twice*, so it's not surprising you got caught :) Cheers PeteS
