Great! Thanks
On Tue, Jun 24, 2014 at 11:30 AM, Adrian Chadd <adr...@freebsd.org> wrote: > Hi! > > Absolutely. I'll see if I can find the register. > > > -a > > > On 23 June 2014 22:34, mahaveer gupta <mgupta1...@gmail.com> wrote: > > Hi Adrian, > > > > I was referring to the Scrambler module in the 802.11 protocol stack- > > http://standards.ieee.org/getieee802/download/802.11-2007.pdf > > (Section 17.3.5.4) > > > > At a high level, the data bits from the mac layer are XORed with a random > > sequence before coding with a convolutional code. At the receiver, the > > decoded output is XORed with the same sequence to recover the actual data > > bits (descrambling). I think scrambling helps in randomizing the data, > > especially if it has long sequence of 0s and 1s > > > > However, the XOR sequence used to scramble is chosen randomly based on a > > seed. I was trying to fix the random seed so that a fixed sequence is > > choosen for scrambling. Basically, I am trying to make the card transmit > a > > fixed (known) sequence of symbols at the physical layer for an > experiment. > > However, the random scrambling seed is making the same data bits to map > to > > different PHY symbols. > > > > Hope this helps, please let me know if you have a question > > > > Thanks, > > M > > > > > > On Sun, Jun 22, 2014 at 11:18 PM, Adrian Chadd <adr...@freebsd.org> > wrote: > >> > >> Hi, > >> > >> Would you mind describing in more detail what it is that you're after? > >> > >> > >> -a > >> > >> > >> On 22 June 2014 14:11, mahaveer gupta <mgupta1...@gmail.com> wrote: > >> > Hello, > >> > > >> > Does anyone know how to fix the scrambler seed to a specific value in > >> > ath9k. > >> > > >> > I could find a relevant code for ath5k in ath5k/reg.h, the following > >> > lines > >> > seem to control the scramble seed. > >> > > >> > #define AR5K_DIAG_SW_EN_SCRAM_SEED_5210 0x00000400 /* Enable > fixed > >> > scrambler seed */ > >> > #define AR5K_DIAG_SW_EN_SCRAM_SEED_5211 0x00000200 > >> > #define AR5K_DIAG_SW_EN_SCRAM_SEED (ah->ah_version == > AR5K_AR5210 ? > >> > \ > >> > > AR5K_DIAG_SW_EN_SCRAM_SEED_5210 > >> > : > >> > AR5K_DIAG_SW_EN_SCRAM_SEED_5211) > >> > #define AR5K_DIAG_SW_ECO_ENABLE 0x00000400 /* [5211+] */ > >> > #define AR5K_DIAG_SW_SCVRAM_SEED 0x0003f800 /* [5210] */ > >> > #define AR5K_DIAG_SW_SCRAM_SEED_M 0x0001fc00 /* Scrambler > >> > seed > >> > mask */ > >> > > >> > Could someone please confirm if similar option is available with ath9k > >> > also? > >> > I couldn't find one > >> > > >> > -- > >> > Thanks, > >> > M > >> > > >> > _______________________________________________ > >> > ath9k-devel mailing list > >> > ath9k-devel@lists.ath9k.org > >> > https://lists.ath9k.org/mailman/listinfo/ath9k-devel > >> > > > > > > > > > > > -- > > Thanks, > > M > -- Thanks, M
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