[hpsdr] I didn't think it would happen again "PING"

[Nyall Davies]

May I encourage you by saying that we were digitally null steering in Radar 
some 10 years ago when I left the industry. We talked in terms of having N 
auxiliary antennas to put N nulls in the beam to get rid of jammers - the 
algorithms became quite compicated then.

When I first started exporing digital radio and saw that the AD6620 could 
process two channels (although at half rate) my immediate reaction was that 
I could have a null cancellor without any more hardware.

Nyall
G8IBR

----- Original Message ----- 
From: "John B. Stephensen" <kd6ozh at comcast.net>
To: <hpsdr at hpsdr.org>; "Murray Lang" <murray.lang at metoceanengineers.com>
Cc: <hpsdr at hpsdr.org>
Sent: Thursday, August 24, 2006 2:29 PM
Subject: Re: [hpsdr] I didn't think it would happen again "PING"


> ***** High Performance Software Defined Radio Discussion List *****
>
> The carrier is just 2 DC levels (I and Q) at baseband which are the cosine
> and sine of the phase angle of the carrier multplied by the amplitude of 
> the
> carrier.
>
> 73,
>
> John
> KD6OZH
>
> ----- Original Message ----- 
> From: "Murray Lang" <murray.lang at metoceanengineers.com>
> To: <hpsdr at hpsdr.org>
> Cc: <hpsdr at hpsdr.org>
> Sent: Thursday, August 24, 2006 02:58 UTC
> Subject: Re: [hpsdr] I didn't think it would happen again "PING"
>
>
>> ***** High Performance Software Defined Radio Discussion List *****
>>
>> Thanks Eric,
>>
>> By baseband I assume this means I/Q. But what needs to be shifted is the
>> carrier, not the modulation. Maybe you have answered that and I just 
>> can't
>> see it. Apologies if this the case.
>>
>> Murray - VK6HL
>>
>> At 10:37 AM 24/08/2006, Eric Blossom wrote:
>> >On Thu, Aug 24, 2006 at 09:22:30AM +0800, Murray Lang wrote:
>> > > ***** High Performance Software Defined Radio Discussion List *****
>> > >
>> >
>> > >
>> > > I have a rudimentary understanding of QSD. My question was really a
> more
>> > > specific one: what is the mathematical function applied to I and Q in
>> > > software that will produce a constant phase shift on the carrier that
> it
>> > > modulates? I wasn't really expecting anyone to answer. When I have a
>> > better
>> > > understanding of the math (I'm working on it) then I'll be able to
> answer
>> > > it myself. Something doesn't smell right though - something about
>> > frequency
>> > > response of the I/Q output. Anyway, I'll get over it.
>> >
>> >You can apply a constant phase shift of theta radians of a complex
>> >baseband signal by multiplying it by e^(j theta) == cos(theta) +
>> >sin(theta) * j
>>
>> >Eric, K7GNU
>>
>>
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