Hi..
I am referring to the RS encoder example given in sec 8.3.3.5.1 of 802.16-2004 standard. I have a confusion regarding the RS parity bytes that are generated here. I am using a LFSR RS Encoder (as defined in page 172, fig 6.13 for ECC book by Lin and Costello). I am assuming that the highest order byte of the randomized data is 0xC1 and the LS Byte is D4. With this assumption I clock in bytes in the Encoder in the following order.
1st byte into the encoder : 0xC1
2nd ---"---------------------- : 0x1A
last Byte :0xD4
if I do this (and donot puncture the codes.. say) I get 0x23, 0x24, 0xfe, 0x77, 0xf8, 0x3d, 0x53, 0xf0, 0xdc, 0x10, 0xcf, 0x08, 0xaa, 0xfd, 0x5a, 0x97 as 16 parity bytes.
I also found out that if I clock the bytes in the opposite order (0xD4,...,0xC1) the parity bytes as defined in the standard... but the parity bytes are the LS Bytes in a RS Code word and hence have to be prefixed to the LS Bytes of the message word... I could not find any contribution with any details on this.. can someone throw some light on this.
Thanks in advance,
Milind