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Old February 28th 11, 05:14 AM posted to rec.radio.amateur.antenna
Richard Clark Richard Clark is offline
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Default No comment three antennas - duplex

On Thu, 24 Feb 2011 17:06:39 -0800, Jim Lux
wrote:

No.. the original article was talking about low power 802.11/802.16
systems (which radiate less than a watt).. At that power level, the fact
that a suitably good linear amplifier is going to consume a fair amount
of power (20% efficiency would be doing well) is insignificant next to
the power consumed by the digital processing necessary to implement the
cancellation algorithm.


As I said, how that finds its way into antenna system consideration
still remains a mystery.

No.. I would expect that this would actually work fairly well. The idea
is to allow full duplex operation, rather than the current half duplex
used in, e.g., 802.11b/g. That would double the throughput (if traffic
on the network were symmetric).


Expectation is not explanation and recital of full duplex vs half
duplex is a duplication of what has been already offered.

If you want to run full duplex, you have to have some way to "see" the
received signal in the face of a much larger transmit signal. Since
you're transmitting, you've got a copy of the transmit signal, so it's
really a matter of figuring out what the transfer function is from
transmitter to (self)receiver. If the external environment were fixed,


And there is the nut of contention. Software will have to accommodate
to variation in environment and throughput suffers. This is old
stuff. The magic of computation still admits of cost galore. More
money for poor transfer doesn't add any sparkle to market
possibilities.

73's
Richard Clark, KB7QHC