Performance of MC-CDMA with pilot code and blind equalization algorithm

by Lesmana, Joseph Sam

Various methods and techniques have been introduced and applied to

advance the state of the art of mobile wireless communications technology. For

example, some techniques are applied to overcome the problem of multipath caused

by the mobile environment. Multipath produces replicas of the wanted signal which

arrive at the receiver with different time delays. If not dealt with properly, this

environment will greatly deteriorate the quality of the wanted signal. The so-called

multiuser feature of many wireless communication systems will also add some

interference to the signal of interest.

This thesis makes an attempt to improve the performance of wireless

communication systems that use either pilot-based or blind equalization techniques

to obtain channel side information. Specifically, these techniques are concerned with

the estimation of multipath parameters in order to improve system performance. By

inserting some pre-defined code which is called a pilot code on each pre-defined

segment of a data block, we can recover the signal by pilot-based methods. Using an

adaptive method, some knowledge of the channel characteristics and input source,

we can achieve acceptable error rate using blind equalization as an alternate solution to pilot-based. Finally, new enhancements are added to blind equalization to improve

its performance further.