what is main deffrent between GSM and CDMA

[gnds]

hi
I want nots for the deffrents
or properteise of CDMA

 

[A.Anand Srinivasan]

GSM mostly uses frequency division multiple access in which each user has a separate carrier freq about 200kHz apart.... CDMA uses same frequency for all communication efficiently conserving bandwidth..... in CDMA the message is encoded using a psuedo random sequence which can be decoded only by the user for which it was encoded for and for users it would be useless....... CDMA is faster than GSM and more secure....

 

[RFCMOS]

hi,

Modulation used by GSM and CDMA are different. Basically, GSM uses GMSK (MSK with gaussian filtering) while CDMA uses QPSK.
I Hope this helps

 

[lmjandy]

GSM uses GMSK while CDMA uses QPSK
does it mean CDMA is two times faster than GSM?

 

[ricksidd]

GSM : TDMA
CDMA : Spread Spectrum

 

[A.Anand Srinivasan]

GSM used both TDMA and FDMA in 2G itself.... they r bringing even more in 3G.... how do you say CDMA is spread spectrum.... isnt CDMA coded FDMA??.... isn't spread spectrum supposed to vary its frequency and time slots....

 

[ck84]

What are the frequency of GSM and CDMA? Can someone advise me?

 

[RFCMOS]

Hello,

Please refer to the following link for GSM and CDMA frequency bands:

https://en.wikipedia.org/wiki/GSM_frequency_ranges.

I hope this helps.

RFCMOS