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question regarding the acquisition and tracking of signals



Jan 1, 1970
question about acquiring and tracking a signal. Maybe its
simple but I am missing some point there.
Consider a CDMA DS SS signal. Assuming that we are transmitting the
code alone and we are trying to decode the code. At the receiver end I
have come across a lot of literature that we have 3 parameters: the
frequency, code phase and delay have to be determined. Assume here
that only the code phase and delay have to be determined and that the
frequency has been taken care of first.
In this case , is the acquiring the process of determing the code
delay or code phase? If it is code phase, then is it trying to
determine the position of the beginnig of the received code with
respect to the locally generated clock? Because every time you are
generating a local code to correlate with the incoming code you have
the same frequecy of the clock except that its phase is different.
Atmost the differece is one chip length. So is acquiring trying to get
the two codes in synchronization thereby getting the clock phases to
be the same? If so how does one know that one is acquiring the proper
code.Remember till now there is no information about the correlation
of the acquired and locally generated codes.
In the other scenario of trying to get to the correlation to be
maximum by finding the delay of the code: in acquisition do we,
irrespective of where the receiver is being clocked to generate the
local code, just find the delay by serial shift correlation or some
And during tracking in the next stage try and get the receiver clock
to be in synchrony with the incoming code generation. I think it is
the later.It is here that I fail to understand the use of early late
detector for tracking. Is it always that one acquires in differences
of half chip delays and tries to track it to within a half chip? The
receiver may start clocking at any other time apart from half the chip
Is my understanding of this concept right? If not I would greatly
appreciate any help in correcting my understanding since I really need
to get this straight.
Looking forward to your replies,

Ps: Are any of the assumptions that I make lead to wrong conclusions
like the above?Please also let me know.