didac
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There's a million ways to see the things in life
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manresa,spain
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Hi frank, Well I think that many papers published under the term "correlation receiver" are made by people of signal processing(I go to a phd thesis defense one or two months ago and they assume they receiver is an antenna, a LNA and directly an ADC-I made a simple calculation and I estimate something like 80 Gigasamples/second, no comments...-) that are more interested in algorithms for synchronization,demodulation,channel estimation and so on, I know some of this guys at my university and when you ask them "how much power will consume this receiver?" they didn't know what you are talking about. This method will be useful for something like a home-theater were you are connected to electrical network, but for a wireless portable device your battery will die very fast.
About your comments about the integrator or the LPF I think they are correct(I didn't make the system election, I worked in UWB as my master thesis that was part of a Phd thesis of the department).
About the use of gaussian pulses(or derivatives) I think that the question refers to the transmitter,you must use a good filter to do the pulse shaping(I didn't see a generator that directly generates a pulse FCC,Europe or Japan mask compliant), in UWB I think that instead of talking of a power amplifier we must start talking about a "power attenuator".
For the possibility of using a LPF before the mixer(thus reducing the BW,then reducing the ADC BW or the integrator BW) I think it's possible but must be validated by a system simulation seeing how BER degrades. As in IR-UWB there's the possibility of trade-off data rate using processing gain in the form of pulse repetition(sent each bit in more than one pulse) probably it will not be very killer(but you will loose data rate), but I've never done myself the system level simulation filtering the received pulse before the mixer so I cannot tell you for sure the effect. I'm sorry that I cannot enter into details about the system architecture with I worked(and from time to time I still work) due to the fact that there is a NDA in the middle. I will suggest you to look a book(maybe you know it): "UWB theory and Applications",Ian Oppermann,Matti Hämäläinen and Jari Iinatti,John wiley & Sons,Ltd. Probably if you've been working a little bit with UWB it's not necessary, but includes a raw(not FCC compliant) transceiver for IR-UWB made with correlation receiver.
Also my research group has published a couple of papers on UWB: "A Low-Power Template Generator for Coherent Impulse-Radio Ultra Wide-Band Receivers" "Low Noise Amplifiers for Low-Power Impulse-Radio Ultra Wide-Band Receivers" Both of them by Enrique Barajas Ojeda and available on the proceedings of "The 2006 IEEE International Conference on Ultra-Wideband". Three more articles are accepted for publishing but they are not available this day. Hope it helps,
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