Data rate in 802.22 depends on the following parameters

· No. of bits per symbol

· Coding rate

· Cyclic prefix

· Symbol duration


Data rate in CR is calculated as


Data Rate = Bit count in one symbol/Symbol duration 

Bit count in one symbol = subcarrier count * no. of bits * coding rate

 = 1440*2*(1/2) where Subcarrier count = 1440        // Ref Table 201 page 310 IEEE802.22-2011

 = 1440


No. of bits is based on modulation technique (QPSK default)

Modulation
No. of bits per symbol
BPSK
1
QPSK
2
16-QAM
4
64-QAM
6

 

Coding rate = ½ (default)

Coding Rate
Data bits
Redundant bits (n-k)
1/2
1
1
2/3
2
1
3/4
3
1
4/5
4
1

 

Cyclic prefix = 1/16 (default)

Cyclic prefix
 
1/4
1/8K
1/16
1/64

 

Symbol duration = sub carrier spacing/cyclic prefix = 317.38

Data rate = bit count in one symbol/symbol duration

 = 1440/317.38

 = 4.53 Mbps