FDMA和CDMA之间的区别

1.频分多址(FDMA)：
FDMA是一种信道化协议，其中带宽被分为各种频带。每个站点都分配有频段来发送数据，并且该频段一直为特定站点保留，具体如下：

不同站点的频带被未使用的频率的小频带分隔开，未使用的频带被称为防止站点干扰的保护频带。就像数据链路层中的访问方法一样，其中每个站的数据链路层告诉其物理层从传递给它的数据中获取带通信号。该信号在分配的频带中创建，并且在物理层没有物理多路复用器。

2.码分多址(CDMA)：
在CDMA中，所有站都可以同时发送数据。它允许每个站点始终在整个频率上传输数据。多个同时传输被唯一的代码序列分隔。每个用户都分配有唯一的代码序列。

在上图中，有4个标记为1、2、3和4的站。分配有相应站d ₁ ，d ₂ ，d3和d _4的数据以及分配有相应站c ₁ ，c ₂ ，c _3的代码和c ₄ 。

FDMA和CDMA之间的区别：

Sr. No.	FDMA	CDMA
1.	FDMA stands for Frequency Division Multiple Access.	CDMA stands for Code Division Multiple Access.
2.	Sharing of bandwidth among different stations takes place.	There is sharing of both i.e. bandwidth and time among different stations takes place.
3.	There is no need of any codeword.	Codeword is necessary.
4.	There is only need of guard bands between adjacent channels are necessary.	In this, both guard bands and guard time are necessary.
5.	Variable transmission rate is difficult.	Variable transmission rate is easy..
6.	There is no Near-far problem.	There is existence of Near-far problem.
7.	In this, power efficiency can be reduced.	In this, full power efficiency is required.
8.	Capacity of system is low.	Capacity of system is large.
9.	It is costly.	In this, only installation is costly and operating cost is low.
10.	It is less flexible.	It is more flexible.