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An Adaptive IEEE 802.15.4a TH-TDMA UWB Industrial Field Level Network

Farah Haroon and Kazi. M. Ahmed
Telecommunications Field of Study, Asian Institute of Technology, Thailand

Abstract— We introduce the deployment of IEEE 802.15.4a in industrial field level communication, which is unexplored so far. Impulse radio-time hopping ultra wide band (IR¬TH UWB) physical layer is robust against dense multi-path fading and interferences. However, we propose an adaption in medium access control (MAC) to meet the major constraints of reliability and timeliness. The self configuring MAC overcomes the difficulties and limitations of specified carrier sense multiple access/collision avoid¬ance (CSMA/CA), slotted Aloha and guaranteed time slots (GTS) mechanisms. Addressable TH codes in fixed time slots of modified superframe structure are used to handle asynchronous alarm requests during ongoing synchronous transmissions. Traffic modeling is presented and we derive the expressions for accessing delays of both the synchronous and asynchronous data traffics. The realistic industrial non line of sight (NLOS) channel environment of IEEE 802.15.4a is employed and the respective power delay profile (PDP) and cumulative density function (CDF) of instantaneous signal to noise ratio (SNR) are found. Moreover, for large number of resolvable multipath components (MPCs), we also propose a reduced complexity adaptive SRake receiver, which efficiently recovers the weak IR-TH UWB signals in dense multipath propagation and strong noise. In addition, we evaluate the error performance of the proposed receiver architecture in comparison with conventional SRake and additive white Gaussian noise (AWGN) correlation receivers. Our simulation results show a significant performance im¬provement with very less number of SRake fingers.

Index Terms— Adaptive SRake receiver, field level industrial network, IEEE 802.15.4a, industrial NLOS environment, synchronous and asynchronous data.

Cite: Farah Haroon and Kazi. M. Ahmed , "An Adaptive IEEE 802.15.4a TH-TDMA UWB Industrial Field Level Network," Journal of Communications, vol. 5, no. 7, pp.571-580, 2010. Doi: 10.4304/jcm.5.7.571-580