Physical Layer Model of the Impact of Bluetooth on IEEE 802.11b July 2000 doc.: IEEE 802.15-00/220r0 July 2000 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 Peter J. Voltz, Polytechnic University

Bluetooth interferer modeled as tone jammer July 2000 doc.: IEEE 802.15-00/220r0 July 2000 Physical Layer Simulation Model For Impact 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 Peter J. Voltz, Polytechnic University

Processing Options Basic Processing (BP) BP + MF July 2000 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 July 2000 Tapped Delay Line Channel Model Channel Impulse Response Peter J. Voltz, Polytechnic University

Pick Largest Pick Largest D-QPSK D-QPSK Channel Channel Matched Filter July 2000 Channel Matched Filter Channel Pick Largest Pick Largest D-QPSK D-QPSK Peter J. Voltz, Polytechnic University

Communication System Analysis July 2000 Communication System Analysis Peter J. Voltz, Polytechnic University

July 2000 Peter J. Voltz, Polytechnic University

Output of Receiver due to 802.11 input July 2000 Output of Receiver due to 802.11 input Where Peter J. Voltz, Polytechnic University

and the channel is clear, then and July 2000 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 July 2000 Response to Interference Frequency offset, , has two effects Peter J. Voltz, Polytechnic University

1. Effective amplitude of interferer is multiplied by July 2000 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

July 2000 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 to digital sine wave correlation effect July 2000 Effect of frequency offset due to digital sine wave correlation effect Peter J. Voltz, Polytechnic University

Effect of frequency offset due to digital sine wave correlation effect July 2000 Effect of frequency offset due to digital sine wave correlation effect Peter J. Voltz, Polytechnic University

Effect of frequency offset due to digital sine wave correlation effect July 2000 Effect of frequency offset due to digital sine wave correlation effect Peter J. Voltz, Polytechnic University

July 2000 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 July 2000 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