RAKE RECEIVERS in CDMA:

In CDMA, rake receivers are used to synchronize multipath signals.

Rake receiver consists of several sub receivers called “Fingers”. Each finger is assigned to each delay component. Then fingers are merged to synchronize signals. This technology becomes limited because fingers are limited and

unassigned delay component will cause interference.

LTE RECEIVERS:

LTE receivers do not need to synchronize with individual delay component.

Guard Periods are used between every two OFDMA symbol. Guard Period may consist of both Cyclic Prefix and Cyclic Suffix

or only Cyclic Prefix. Cyclic Prefix: last part of following symbol. Cyclic Suffix: initial part of previous symbol.

Condition for avoiding inter symbol interference:

Tcp >= Tdelay

SYMBOL WITH CYCLIC PREFIX:

ADVANTAGES OF CYCLIC PREFIX:

It prevents from inter-symbol interference. It provides robustness, data re-transmitted can be utilized.

DISADVANTAGE OF CYCLIC PREFIX:

It reduces data capacity and data rate as the duration of cyclic prefix increases.