Code division multiple access in wireless communication

FDMA (Frequency Division Multiple Access), seperates the frequency intervals by allocating different frequency intervals to the users. But TDMA (Time Division Multiple Access), allocates different time-intervals to the users. On the other hand CDMA (Code Division Multiple Access) system allocates total frequency band to the all users. It also seperates the users by using the PN (Pseudo Noise) series with the condition of modulating the signs of PN series. Since there is no space between codes, capasity becomes greater than the others. In addition to this, CDMA is a wide band system too, since it is a multi-access technology using spreaded-spectrum technic. Because of this some disadvantages of narrow band systems could be eliminated. In this study, The development of mobile communication system researched and performances of a CDMA technic is evaluated. Key Words : UMTS, CDMA