Yep, I'm aware of that. On that note, their FCC and SEC filings are pretty interesting.
https://www.google.com/search?num=20&safe=off&q=sirius+%22FM-3%22+%22TT%26C%22&oq=sirius+%22FM-3%22+%22TT%26C%22&gs_l=serp.3...466273.468341.0.468752.7.7.0.0.0.0.287.1073.2j4j1.7.0.ckpsrh...0...1.1.64.serp..7.0.0.2rZ6gnDtP7M https://www.google.com/search?num=20&safe=off&q=siriusxm+right+hand+circular+polarization&oq=siriusxm+right+hand+circular+pol&gs_l=serp.3.0.33i21.9261.17199.0.19298.18.18.0.0.0.0.114.1520.16j1.17.0....0...1.1.64.serp..1.12.1070.uCsnuHPRz8Y On Sun, Apr 10, 2016 at 3:03 PM, Andy Walls <a...@silverblocksystems.net> wrote: > Just to be clear, Sirius is different than XM (even though they merged). The > lower edge of the 12.5 MHz XM allocation is at 2332.5 MHz, IIRC. The upper > edge of the 12.5 MHZ Sirius allocation is there as well. > > Sirius does have patents on hierarchical modulation, which I'm guessing they > would use in the Sirius band. > > Regards, > Andy > > On April 10, 2016 5:36:08 PM EDT, Chris Kuethe <chris.kue...@gmail.com> wrote: >>Thanks to Steve for hitting me with a clue-stick. For anyone else >>playing along at home, the Sirius patch antenna has an integrated amp >>and takes inline power - a fact that I did not see anywhere. >> >>This test was done with a hackrf tuned to 2.3265GHz, 20Msps, 8MHz >>analog filter - there is clearly something interesting going on when >>inline power is enabled with the "bias=1" argument. >> >>On Sat, Apr 9, 2016 at 6:32 AM, Andy Walls >><a...@silverblocksystems.net> wrote: >>> >>> >>> On Fri, Apr 8, 2016 at 10:48 AM, Andy Walls >><a...@silverblocksystems.net> >>> wrote: >>>> >>>> >>>> > The audio codec is proprietary and not documented anywhere >>AFAIK >>>> > so >>>> > even if you demod the bitstream, you won't be able to do >>much >>>> > with it. >>>> >>>> > Thank you all for the conversation, it is pretty interesting. >>That >>>> > makes sense >>>> > that they have a proprietary protocol, it's a shame though. Is >>the text >>>> > that >>>> > comes through encoded in a proprietary way? >>>> > >>>> > Does anyone know what the frequency of channel 1 is on (I'd like >>to see >>>> > if I >>>> > can even see the signal popping up above the noise)? >>>> > >>>> > ~Jason >>>> >>>> The XM center freqs are shown here: >>>> >>>> >>>> >>https://www.rohde-schwarz.com/us/technologies/satellite-broadcast/xm-satellite/xm-satellite-technology/xm-satellite-technology_55613.html >>>> >>>> The Sats are QPSK, the terrestrial is COFDM. >>>> >>>> That page also states the audio codec for voice programming is AMBE, >>and >>>> AAC+ for all other programming. >>>> >>>> >>>> The XM radio patents give you a lot of clues: >>>> >>>> >>https://www.google.com/search?tbo=p&tbm=pts&hl=en&q=inassignee:%22Xm+Satellite+Radio+Inc.%22 >>>> >>>> Images 4 and 6 of this one: >>>> >>>> >>https://www.google.com/patents/US7020217?dq=inassignee:%22Xm+Satellite+Radio+Inc.%22&hl=en&sa=X&ved=0ahUKEwj5ycbeoP_LAhXEXh4KHWSdDeA4HhDoAQgwMAM >>>> Image 4 of this one: >>>> >>>> >>https://www.google.com/patents/US6510317?dq=inassignee:%22Xm+Satellite+Radio+Inc.%22&hl=en&sa=X&ved=0ahUKEwikn4Ogof_LAhVIJx4KHYaYCt44KBDoAQhTMAg >>>> >>>> And maybe the most useful I've skimmed: >>>> >>>> >>https://www.google.com/patents/US7123875?dq=inassignee:%22Xm+Satellite+Radio+Inc.%22+MCM&hl=en&sa=X&ved=0ahUKEwidqpT1of_LAhUFXh4KHXqIDuEQ6AEIKjAC >>>> Images 1, 5, and 6. >>>> >>>> This particular patent also indicates that after the demod, RS >>decoder, >>>> viterbi decoder, and deinterleaver, that an MPEG TS *might* be the >>>> transport multiplex. >>>> >>>> The images show that the decryption happens after all the FEC and >>>> deinterleaving is handled and also after SL (service layer) >>decoding. >>>> The I2C connected external NVRAM is likely where the program >>decryption >>>> key is stored (inside of a tamper boundary), according to other >>internet >>>> pages from 7 years ago. >>>> >>>> So I'm guessing you have to totally demodulate and decode one of the >>SAT >>>> or terrestrial channels, and then dig around in a (hopefully MPEG) >>>> transport stream to find your unencrypted "Channel 1" >>>> >>> >>> The STA400A datasheet gives a lot of good information about the XM >>signal >>> characteristics, bit rate, RCC filter bandwidth, code rates and >>puncturing, >>> proper order of FEC blocks, etc.: >>> >>> http://www.chipfind.net/datasheet/pdf/stmicroelectronics/sta400a.pdf >>> >>> Enough info to give one half a chance of getting the demodulation >>correct. >>> It also talks a little bit about the frame structure. >>> >>> This MAXIM 2140 App Note has a yet another picture of the spectrum >>> allocation, that also shows Sirius' and WCS' allocations in context: >>> >>> http://pdfserv.maximintegrated.com/en/an/AN3851.pdf >>> >>> I also found a Sirius patent that talks about an overlay modulation, >>but it >>> wasn't clear to me if it was being applied to the XM satellite >>signals. >>> >>> Regards, >>> Andy >>> >>> _______________________________________________ >>> Discuss-gnuradio mailing list >>> Discuss-gnuradio@gnu.org >>> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >>> > -- GDB has a 'break' feature; why doesn't it have 'fix' too? _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
