Question about OFDM and incoming data tracking

[QMA]

OFDM: reception

hi friends
i want to know whaen i transmit some, data then at the receiver end how will i know that now my data is coming means at the very start how can i keep track of my data. after receiving and detecting the initial data i can keep track of my transmission that now this frame is coming and now this. but how will i come to know that when my first frame is starting at the receiver???

Moreover is it possible theoratically viz can i simulate it in matlab.

 

[maomun]

OFDM: reception

Hi, QMA

As u said, it can be done by frame design or by identical cyclic ,prefix postfix Ex. in your simulation before u recieve useful data u could set known initial bit like "0101...1" then [GI,data]0101....1[GI,data] till the end of frame in meaning to track symbol by symbol or just frame by frame .

It's better if u look at WLAN's standard like IEEE 802.11a,g or WIMAX that each standard have how physical techinqe used for frame or packet design.

At last, almost matlab companion about ofdm from any text book or some link in www. assume perfect synchronize and detection.

 

[mhamed]

OFDM: reception

what you are looking for is a very complex topic known as synchronization. there are a number of synchronization methods depend on your modulation. for example AM modulation dose not need any synchronization while OFDM and CDMA calls for it. simply search on OFDM synchronization topic.