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J. MIKULKA, S. HANUS, BLUETOOTH AND IEEE 802.11B/G COEXISTENCE SIMULATION
Bluetooth and IEEE 802.11b/g Coexistence Simulation
Jan MIKULKA, Stanislav HANUS
Dept. of Radio Electronics, Brno University of Technology, Purky
ˇ
nova 118, 612 00 Brno, Czech Republic
mikulkajan@seznam.cz, hanus@feec.vutbr.cz
Abstract. This paper deals with the coexistence simulation
of Bluetooth and Wi-Fi physical layers. Bluetooth and Wi-Fi
systems share the same ISM 2.4 GHz frequency band and
therefore using both systems in the same area may cause in-
terference. A model of Bluetooth and IEEE 802.11b/g physi-
cal layers was made in Mathworks Matlab Simulink environ-
ment. A new simulation of Bluetooth and Wi-Fi coexistence
is presented. The results in graphical form are introduced
as a dependence of BER on E
b
/N
0
and BER on power ratio
of Bluetooth and Wi-Fi systems.
Keywords
Bluetooth, Wi-Fi, IEEE 802.11b, IEEE 802.11g, Coex-
istence.
1. Introduction
Bluetooth is an industrial specification for WPAN
(Wireless Personal Area Network) networks, which oper-
ate in short-range radio frequency band. Bluetooth enables
exchanging information between various devices, printing
on Bluetooth printer and connecting various PC peripherals
(wireless mouse, keyboard, hands-free, etc.).
The Bluetooth system is widely used in office environ-
ment, where it can be greatly disturbed by other sources
of ISM 2.4 GHz interference. Strong interference can be
caused by the Wi-Fi [1] communication standard, which
uses the same ISM 2.4 GHz frequency band. Many portable
devices support both communication standards and can be
connected to the Wi-Fi access point and Bluetooth headset
or Bluetooth modem at the same time. Bluetooth and Wi-Fi
interference can be reduced by Adaptive Frequency Hop-
ping (AFH) [2], but this noncollaborative method is imple-
mented in Bluetooth 1.2 and later revisions of the standard.
The present work deals with non-AFH coexistence simula-
tions.
2. IEEE 802.11b Physical Layer
Wi-Fi is developed by IEEE 802.11 Task Group and
is aimed on WLAN (Wireless Local Area Network) net-
works. Wi-Fi is mainly used for enabling mobile Internet
connectivity in various devices (mobile phones, notebooks,
etc.). IEEE 802.11 uses ISM (Industrial Scientific and Med-
ical) 2.4 GHz frequency band and there are 13 overlapping
22 MHz wide frequency channels defined (Fig. 1). The
most widespread specifications are IEEE 802.11b and IEEE
802.11g (Tab. 1).
2.4 GHz 2.483 GHz
1
1 2 3 4 5 6 7 8 9 10 11 12 13
2
3
4
5
6
7
8
9
10
11
12
13
Fig. 1. Wi-Fi channels.
The first IEEE 802.11 physical layer specification re-
leased in 1997 is called DSSS (Direct Sequence Spread
Spectrum) and employs Barker coding to achieve 1 Mbit/s
(DBPSK) and 2 Mbit/s (DQPSK). In 1999, the IEEE
802.11b specification was released. It was enhanced with
HR/DSSS (High Rate DSSS), which employs Complemen-
tary Code Keying and achieve data rates of 5.5 Mbit/s and
11 Mbit/s (Tab. 1).
Standard Release Data rates Modulation Coding
version [Mbit/s]
802.11 1997 1, 2 DBPSK and DQPSK Barker c.
802.11b 1999 1, 2, 5.5, 11 DBPSK a DQPSK Barker c., CCK
802.11g 2003 up to 54 DBPSK to 64QAM OFDM
802.11a 1999 up to 54 BPSK to 64QAM OFDM
802.11n 2007-8 up to 540 DBPSK to 64QAM OFDM, MIMO
Tab. 1. IEEE 802.11 standards overview.
Standard IEEE 802.11b employs Barker Coding and
CCK (Complementary Code Keying). IEEE 802.11b data
rates are summarized in Tab. 2.
Data Code Modu- Sym. rate bits/ System
rate length lation [MSps] symbol
1 Mbit/s 11 (Barker c.) DBPSK 1 1 DSSS
2 Mbit/s 11 (Barker c.) DQPSK 1 2 DSSS
5.5 Mbit/s 4 (CCK) DQPSK 1.375 4 HR/DSSS
11 Mbit/s 8 (CCK) DQPSK 1.375 8 HR/DSSS
Tab. 2. IEEE 802.11b - data rates specifications.