[hpsdr] Some things worthy of your attention

[Krister Wikström]

Some of you are no doubt familiar with the following, but I'd like to
point your attention to two books that I've found very valuable and in
my humble opinion should be on every serious SDR developer's bookshelf:

1. Peter B. Kenington: RF and Baseband Techniques for Software Defined
Radio, ISBN 1-58053-793-6 (Artech House)
This tome covers practically all there is to SDR.

2. Jouko Vankka: Digital Synthesizers and Transmitters for Software
Radio, ISBN-10 1-4020-3194-7 (Springer)
Great detail regarding transmitters with high linearity and high
efficiency, two things that usually don't go hand in hand.


Regarding the direction for future developments in HPSDR and other
projects, I think it might be a good idea to have a look at the new LXI
standard for interconnecting measuring instruments via the Ethernet.
Ethernet is ubiquitous, cheap and broadband, and lends itself very well
for remote control, wired or wireless. 

Another relevant standard could be the RP3-01 specification from the
OBSAI  base station standard. This spec defines a digital interface
between a remote RF head and the baseband signal processing unit.

I think the present SDR-1000 3-board stack with separate audio and
control interfaces is not very elegant, to put it mildly. I can
understand the initial rationale for using a sound card for the A/D and
D/A conversion, after all most PC:s and all laptops have a sound card.
BUT, as it turned out, most sound cards aren't good enough, a fact that
rather negates the initial idea. We definitely need an all-digital
interface between the RF head and the PC, the sooner the better.

Best regards,

Krister Wikstrom OH2MLQ