Difference Between TDMA and FDMA

Parameter	TDMA	FDMA
Acronym for	Time Division Multiple Access	Frequency Division Multiple Access
Technology	In TDMA radio spectrum is divided into time slots and in each slot only one user is allowed to either send or receive.	In FDMA individual channels are assigned to individual users. Each user is allocated a unique frequency or band.
Bandwidth Sharing	In TDMA single frequency is shared by several users.	Frequency sharing is not allowed. If FDMA channel is not in use, it can’t be utilized by other user to increase or share capacity.
Transmission Scheme	Data transmission for users in TDMA is not continuous and uses buffer-and-burst method.	FDMA is a continuous transmission scheme and after the assignment of channel, base station and mobile transmit simultaneously and continuously.
Use of Duplexers	TDMA uses different time slots for transmission and reception hence no duplexers are required.	In FDMA transmitter and receiver operate at same time hence duplexers are required.
Synchronization/Signal Overhead	Because of slotted Burst transmission high synchronization is required. In addition to this guard slots are required to separate users.	Since it is a continuous transmission scheme hence very few overhead signals are required.
Interference	If guard time is not minimized, the transmitted spectrum expands and causes interference to adjacent channels.	Nonlinear effect in FDMA causes generation of Intermodulation (IM) frequencies which are undesired RF radiations and interfere with other channels in FDMA.
No. of Channels Supported Simultaneously	N=m(Btot-2Bguard)/Bc Where m=max. no. of users supported at each radio channel	N= (Bt-2Bgaurd)/Bc Where Bt=Total Spectrum Allocation Bgaurd=Guard band allocated at the edge of allocated spectrum band BC =Channel Bandwidth.
Mobile System Complexity	High	Less
Equalization	Adaptive equalization is necessary in TDMA systems because of high transmission rates.	Due to large Symbol time intersymbol interference is low thus no or very little equalization is required.
Cell Site System Cost	Low	High, due to single channel per carrier design and costly band pass filters to eliminate spurious radiations at base station.