Product Info
WipLL Radio Technology - Physical Layer System Description
2-4 Airspan Networks Inc. 25030311-08
Table 2-1 shows an example of six orthogonal sequences that can be derived from
seven sub-channels.
Table 2-1: Example of six orthogonal FH sequences
Sequence No. Sub-channels (frequencies)
1
0 1 2 3 4 5 6
2
0 2 4 6 1 3 5
3
0 3 6 2 5 1 4
4
0 4 1 5 2 6 3
5
0 5 3 1 6 4 2
6
0 6 5 4 3 2 1
Up to 32 such sequences, each with up to 99 sub-channels can be pre-configured in
the WipLL ROM. An additional 32 sequences can be configured by the WipLL
operator in the RAM to provide further flexibility.
2.2. Modulation
The WipLL system is based on Continuous Phase Frequency Shift Keying (CPFSK)
modulation. Frequency Shift Keying uses m different frequencies for m symbols.
The simplest FSK is binary FSK, where 0 and 1 correspond to different frequencies:
Figure 2-3: Graph displaying different frequencies for 0 and 1 bits
FSK is similar to non-linear analogue FM, but with digital modulation.