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spikefeet
Joined: 05 Mar 2006
Posts: 31
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 20 Dec 2006 12:37 hi cdma fdma tdma |
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hi guys i read abt cdma fdma tdma.i didnt understand their differences.i would like to know which is superioir and why....
any body can help me plz...........
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bilalkadri
Joined: 12 Oct 2004
Posts: 50
Helped: 1
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| 21 Dec 2006 7:39 Re: hi cdma fdma tdma |
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FDMA is basically Analog technology and the oldst one. TDMA is digital and being used in GSM. CDMA is newest of all, whre all users are allocated a distinct code.
Added after 2 minutes:
For easy and basic understanding I will recommend " Data Comm and Networking" by Behrouz Forouzan
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hisham1976
Joined: 13 Dec 2006
Posts: 8
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| 21 Dec 2006 19:10 hi cdma fdma tdma |
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Hi
In TDMA any user can access each time slot.Many booke say that CDMA is better.
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Enhancer
Joined: 09 Dec 2006
Posts: 57
Helped: 3
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| 21 Dec 2006 22:33 Re: hi cdma fdma tdma |
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First, what is "MA" means:
MA=Multiple Access, which means that many users share the same medium. There are many techniques to share the medium between them;
FDMA=Freq division multiple access:
where each user has its own freq band that is allocated for him all the time.
TDMA=Time division multiple access:
where all the users share the same frequency band but part of the time, i.e. no more than one user can occupy the freq band at the same time.
CDMA=Code division multiple access:
where each user is different than the others by its own code that identify him from all the other users. Hence, all the frequency band is for all users all the time.
If it hepls you, press "Helped me"
KAMAL
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tronix
Joined: 06 Jul 2006
Posts: 121
Helped: 6
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| 31 Dec 2006 9:18 Re: hi cdma fdma tdma |
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Hi
You can also refer to the link :
http://www.edaboard.com/viewtopic.php?t=194999&highlight=
tronix
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magnetra
Joined: 21 Apr 2005
Posts: 260
Helped: 3
Location: 27.45N, 85.20E KTM, NP
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| 02 Jan 2007 15:11 hi cdma fdma tdma |
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Anyone has info or documents on SDMA ( Space Division Multiple Access).
Regards
M
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tarakapraveen
Joined: 18 Jan 2007
Posts: 86
Helped: 4
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| 21 Jan 2007 18:41 Re: hi cdma fdma tdma |
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hi
One Doubt on this topic.
How to differentiate Multiplexing and Multiple Access Exactly?
Since even for both we saying (e.g FDM/FDMA frequency is dividing between users)How that parameter frequency exactly differentiating MA and Multiple Access?
Thanks in Advance
PraveenGoud
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ramysk
Joined: 21 Dec 2006
Posts: 9
Helped: 1
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| 21 Jan 2007 23:04 Re: hi cdma fdma tdma |
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hi to all
1)FDMA: frequency division multiple access and in this technique the total bandwidth is divided between users,i.e. all users send the data on the same time but different frequencies. FDM is the same but the only difference is in FDM we have one transmitter and more than one receiver (like the radio broadcast) but in FDMA we have more than one transmitter trying to access one receiver (like the mobiles trying to access base station).
2)TDMA: time division multiple access and in this technique time is divided between users,i.e. all users send the data on the same bandwidth (the same frequency) but in different time slots. the same concept with TDM.
BOTH FDMA and TDMA are used in GSM
3)CDMA: code division multiple access and in this technique each user is assigned to a certain code that enable the user to extract the information,i.e. all the users send the data at the same time and the same frequency. this technique has a lot of advantages than FDMA and TDMA like Jamming immunity,security, privacy and the number of users that share the same communication channel is greater than FDMA ana TDMA.
CDMA is used in 3G
hope every thing is clear now
bye[/u]
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rami.masadeh
Joined: 26 Oct 2005
Posts: 45
Helped: 3
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| 29 Jan 2007 10:26 Re: hi cdma fdma tdma |
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CDMA is the best technology for mobile telecommunication, it gives you higher bandwidth,
but the modulation and and demodulation is more compicated.
BR
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slayer_zeco
Joined: 02 Mar 2006
Posts: 1
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| 30 Jan 2007 9:54 Re: hi cdma fdma tdma |
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CDMA is better than TDMA.
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xxdymhbh
Joined: 31 Jan 2007
Posts: 2
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| 31 Jan 2007 7:19 Re: hi cdma fdma tdma |
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> CDMA is used in 3G???
FALSE.
For 3G, the standard is WCDMA, CDMA2000, TDSCDMA...
CDMA is used in 2G.
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