17-03-2014, 02:42 PM
CCK Bits-to-Symbol Mapping
Purpose:
To verify the device under test (DUT) correctly maps the raw data bits to
complimentary code keying (CCK) modulated symbols.
Resource Requirements:
• Vector Signal Analyzer (VSA), Rohde & Schwarz FSQ26 or equivalent
• HR/DSSS PHY Station with external antenna jack
• Associated HR/DSSS PHY AP or station with external antenna jack(optional)
• RF Power Splitter, Picosecond 5333 or equivalent
• Controlling Software (Matlab)
Last updated: April 2008
Discussion:
Reference [1] describes the High Rate direct sequence spread spectrum (HRDS/DSSS) physical
layer for the 2.4 GHz band. Section 18.4.6.5 specifies the spreading sequences and modulation
for complementary code keying (CCK) modulation to obtain increased data rates of 5.5 and 11
Mbps utilizing polyphase, orthogonal chipping patterns.
Procedure:
1. For DUT’s that support continuous transmission, configure the DUT to continuously
transmit PSDUs of length ≤ 100 bytes of a known data pattern on channel 6 at a data rate
of 11 Mbps. Otherwise, for burst mode traffic, configure the DUT to associate and
generate continuous ICMP echo request packets of length 100 bytes, and set the Beacon
Interval to 100 ms. In either case, set the modulation to CCK.
2. Configure the trigger on the VSA to capture an entire packet. Demodulate and decode the
frame.
3. Calculate the CRC-16 and CRC-32 values.
4. Verify the content of the received frame against the known data pattern.
5. Repeat steps 1-3, however, change the data rate to 11 Mbps.
Observable Results:
a. The received CRC-16 and CRC-32 values should be identical to the calculated values.
b. The transmitted PSDU data should be identical to the received PSDU data