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IEEE P802.15 Working Group for Wireless Personal Area Networks TM. Physical Layer Model of the Impact of Bluetooth on IEEE 802.11b. Physical Layer Simulation Model For Impact of Bluetooth Interferer on 11Mbps 802.11 Receiver. Bluetooth interferer modeled as tone jammer
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IEEE P802.15 Working Group for Wireless Personal Area NetworksTM Physical Layer Model of the Impact of Bluetooth on IEEE 802.11b Peter J. Voltz, Polytechnic University
Physical Layer Simulation Model ForImpact of Bluetooth Interferer on 11Mbps 802.11 Receiver • Bluetooth interferer modeled as tone jammer • Performance of 802.11 Receiver depends on the following: • Signal to Interference Ratio (SIR) • Signal to Background Noise Ratio • Frequency of Bluetooth Interferer • Multipath Structure • Receiver Processing Peter J. Voltz, Polytechnic University
Processing Options • Basic Processing (BP) • BP + MF • Matched Filter (MF) for collecting multipath energy • BP + MF + EQ • Equalizer (EQ) to correct for Intersymbol Interference (ISI) Peter J. Voltz, Polytechnic University
Tapped Delay Line Channel Model • Channel Impulse Response Peter J. Voltz, Polytechnic University
Channel Matched Filter Channel Pick Largest Pick Largest D-QPSK D-QPSK Peter J. Voltz, Polytechnic University
Communication System Analysis Peter J. Voltz, Polytechnic University
Output of Receiver due to 802.11 input Where Peter J. Voltz, Polytechnic University
Note that if is time limited to Seconds, and the channel is clear, then and Which is the cross correlation between the receivers reference codeword and the particular codeword being received, times the phase factor which carries 2 bits. When a multipath channel is present, the non-zero values of for cause intersymbol interference. Peter J. Voltz, Polytechnic University
Response to Interference Frequency offset, , has two effects Peter J. Voltz, Polytechnic University
1. Effective amplitude of interferer is multiplied by . 2. The discrete sine wave, , is correlated with the 64 CCK codewords and contributes to outputs. Peter J. Voltz, Polytechnic University
Simulation Results for three sample channels.Bluetooth Interferer at 802.11 Band Center.Eb/No = 20 dB for white noise. Peter J. Voltz, Polytechnic University
Effect of frequency offset due todigital sine wave correlation effect Peter J. Voltz, Polytechnic University
Effect of frequency offset due todigital sine wave correlation effect Peter J. Voltz, Polytechnic University
Effect of frequency offset due todigital sine wave correlation effect Peter J. Voltz, Polytechnic University
Conclusions • We have modeled the 802.11b Receiver except for the Equalizer. • Without the equalizer the effect of interference is heavily dependent on the actual channel model. • At 10-4 the SIR varies from about 6 dB to about 18 dB Peter J. Voltz, Polytechnic University
Next Steps • Add the Equalizer into the model • See if the variation due to the channel is reduced • Develop a formula for the Symbol Error Rate (SER) as a function of SIR. • Feed that (SER) formula into the MAC model. Peter J. Voltz, Polytechnic University