Publication: Magyar Közlöny
Issue: MK-2009-104 (Year: 2009, Number: 104)
Era: 2004-2010
Section: 
Paragraph Index: 1921

b) c = the smallest integer greater than or equal to the value of the fraction. After extending the data to an even multiple of 1992 bits, the interleaver shall write the transmission stream into the first 249 octets of each row by taking each consecutive group of eight bits and storing them from the first column to the 249th. The first bit in each group of eight bits shall be stored in the eighth bit position; the first group of 1992 bits shall be stored in the first row, the second group of 1992 bits in the second row, etc. After the FEC is computed on each row, the FEC data (or erasures) shall be stored in columns 250 through 255. The interleaver shall then pass the data to the scrambler by reading out column by column, skipping any octet which contains erasures or all fill bits. All of the bits in an octet shall be transmitted from bit 8 to bit 1. On reception, the de-interleaver shall calculate the number of rows and size of the last (potentially partial) row from the length field in the header. It shall only pass valid data bytes to the higher layer. Annex 10 — Aeronautical Communications Volume III 22/11/07 I-6-12 6.4.3.1.4 Bit scrambling. To aid clock recovery and to stabilize the shape of the transmitted spectrum, bit scrambling shall be applied. The pseudo noise (PN) sequence shall be a 15-stage generator (see Figure 6-2) with the characteristic polynomial: X15 + X + 1 The PN-sequence shall start after the frame synchronization pattern with the initial value 1101 0010 1011 001 with the leftmost bit in the first stage of the register as per Figure 6-2. After processing each bit, the register shall be shifted one bit to the right. For possible encryption in the future this initial value shall be programmed. The sequence shall be added (modulo 2) to the data at the transmit side (scrambling) and to the scrambled data at the receive side (descrambling) per Table 6-3. Note.— The concept of a PN scrambler is explained in ITU-R Recommendation S.446-4, Annex I, Section 4.3.1, Method 1 (see the Appendix to this chapter). 6.4.3.2 MODE 2 CHANNEL SENSING 6.4.3.2.1 Channel busy to idle detection. When a station receives on-channel power of at least –87 dBm for at least 5 milliseconds, then:

Source: https://magyarkozlony.hu/hivatalos-lapok/bfd0d67db9f223889f627fd618725b03526630e2/dokumentumok/d5234fd7275da04023366ab8a434989962a31bdf/letoltes