Processing Gain Information

FCC ID: LDK102039

Operational Description

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FCCID_91349

Test report #20000282F FCC 15.231 for MI-4800B FCC ID: LDK102039 Tested February 2, 2000 EXHIBIT D: PROCESSING GAIN INFORMATION [15.247(E)] PRODUCT NAME: AIRONET 4800B RADIO NAME OF TEST: The Processing Gain of a Direct Sequence System. FCC Part 15.247 (e) specifies: The processing gain of a direct sequence system shall be at least 10 dB. Guidance on measurement by FCC The processing gain may be measured using the CW jamming margin method. The test consists of stepping a signal generator in 50khz increments across the passband of the system. At each point, the generator level required to the produce the recommended Bit Error Rate (10-5) is recorded. This is the jammer level. The output power of the transmitting unit is measured at the same point. The Jammer to Signal (J/S) ratio is then calculated. Discard the worst 20% of the J/S data points. Total losses in a system including transmitter and receiver, should be assumed to be no more than 2 dB. therefore, processing gain = S/N + Mj + Lsys Where : S/N = Signal to noise ratio required at the receiver output for 10-5 error rate of a ideal receiver for your demodulation scheme Mj = Jammer to signal ratio Lsys = System losses (2dB max) Test results : for 1 mb data rate: S/N = 13 dB ; taken from Wireless Information Networks by Pahlavan & Levesque Mj = - 4.2 dB ; worst case jamming margin from tests in lab Lsys = 2.0 dB ; system losses therefore the processing gain at 1mb is 13 dB - 4.2 dB + 2.0 dB = 10.8 dB for 2 mb data rate: S/N = 13 dB ; taken from Wireless Information Networks by Pahlavan & Levesque Mj = - 4.2 dB ; worst case jamming margin from tests in lab Lsys = 2.0 dB ; system losses therefore the processing gain at 2mb is 13 dB – 4.2 dB + 2.0 dB = 10.8 dB Aironet Confidential 1 03/15/00 AHD EMC Lab, 92723 M152, Dowagiac, MI 49047, (616) 424-7014 91349 Exhibit D: Page 1 of 2

Test report #20000282F FCC 15.231 for MI-4800B FCC ID: LDK102039 Tested February 2, 2000 for 5.5 mb data rate: S/N = 13.6 dB ; taken from Harris CCK encoding modulation Mj = - 4.4 dB ; worst case jamming margin from tests in lab (after 20% discard) Lsys = 2.0 dB ; system losses therefore the processing gain at 5.5mb is 13.6 dB - 4.4 dB + 2.0 dB = 11.2 dB for 11 mb data rate: S/N = 16.0 dB ; taken from Harris CCK encoding modulation Mj = - 7.4 dB ; worst case jamming margin from tests in lab (after 20% discarded) Lsys = 2.0 dB ; system losses therefore the processing gain at 11mb is 16.0 dB - 7.4 dB + 2.0 dB = 10.6 dB Jamming Test Setup Sig Gen Power Meter sum split Transmitter Receiver Bit Error Rate Tester RF Systems Engineering AIRONET 2.4 Ghz SPREAD SPECTRUMRADIO, 2nd GEN Jammer Test, R240 eng: J. Friedmann File:FCC025_2.ds4 Date: 3/21/96 AIRONET CONFIDENTIAL dwg: J. Friedmann rev: Aironet Confidential 2 03/15/00 AHD EMC Lab, 92723 M152, Dowagiac, MI 49047, (616) 424-7014 91349 Exhibit D: Page 2 of 2


Document Created: 2000-03-15 08:10:05
Document Modified: 2000-03-15 08:10:05
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