Hello @kartik,
Provided that your server is receiving a string that looks something like this (which it should if you're using jQuery serialize()):
"param1=someVal¶m2=someOtherVal"
something like this is probably all you need:
$params = array();
parse_str($_GET, $params);
$params should then be an array modeled how you would expect. Note this works also with HTML arrays.
Hope it works!!