System Level Design of Low Rate, Low Power 3.1-5GHz IEEE 802.15.4a UWB Transceiver for Medical Monitoring Applications Imen Barraj, Hatem Trabelsi, and Mohamed Masmoudi National School of Engineering of Sfax, University of sfax, Department of Electrical Engineering, Micro-Electro Thermals Systems laboratory (METS), Tunisia Email: imen.barraj@gmail.com, hatem.trabelsi@isetsf.rnu.tn, mohamed.masmoudi@enis.rnu.tn Abstract—Low power consumption is one of the main targets in designing a radio for a Wireless medical devices for healthcare monitoring applications. The IEEE 802.15.4a standard has proprieties that make it a viable solution for this type of applications and environments. IEEE 802.15.4a standard adopts Impulse Radio Ultra Large Band (IR-UWB) to afford low data rates, low power and low complexity communication systems with enhanced communication range and robustness. This paper discusses the architecture parameters selection for low power, monolithic wireless sensor like frequency allocation, data rate, mean PRF, pulse shape and radio architecture. Then, link radio budget parameters required for the transceiver implementation have been established. Index Terms—IR-UWB, IEEE 802.15.4a, link budget, transceiver, Medical monitoring, non coherent receiver I. INTRODUCTION Wireless sensor networks have been used for many applications including healthcare monitoring and medical applications. There are increasing requirements for the vital sign monitoring systems as population aging is progressing rapidly in many industrialized countries which is accompanied by an even more dramatic increase in the number of old people suffering from chronic diseases and disabilities [1]. Low power and Low cost are the most important criteria for designing an emerging sensor network for healthcare monitoring. IEEE 802.15.4a standard has proprieties that make it a promising standard for this type of applications due to the large data bandwidth, the excellent immunity to interference with nearby channels, the coexistence with others systems and the extremely low emitted power spectral density. Ultra Wide Band (UWB) signals are usually defined as signals having a bandwidth of at least 500MHz or at least 20% of the center frequency set to -10dB [2]. The transmitted power spectral density (PSD) should be less than - 41.3dBm/MHz and having a maximum peak power level of 0dBm/50MHz. The Federal Communications Commission (FCC) allocated the unlicensed frequency Manuscript received December 10, 2013; revised February 27, 2014. band from 3.1GHz to 10.6GHz for the UWB application except 5-6GHz ISM band assigned for WLAN applications [3]. Figure 1. Generic architecture of the sensor node The wireless sensor node should be able to operate for severs years under battery energy supply. A generic architecture of the expected devices node is shown in Fig. 1. It typically acquires vital signal data from different medical sensors then it transmit them to a remote personal server, where they will be analyzed with appropriate software. In this paper, we focus on the RF transceiver front end. Section II describes transceiver architecture design selection. In section III, system level analysis has been detailed. Section IV concludes this paper. II. IEEE 802.15.4A TRANSCEIVER ARCHITECTURE DESIGN SELECTIONS A. Frequency Allocation The set of operating frequency bands is defined in Table I [4]. IEEE 802.15.4a standard support three band of operation: sub-gigahertz band, which consists of a single channel and occupies the spectrum from 249.6MHz to 749.6MHz, low band, which consists of four channels and occupies the spectrum from 3.1GHz to 4.8GHz and high band, which consists of eleven channels and occupies the spectrum from 6.0GHz to 10.6GHz. For the sub-gigahertz operation, channel 0 is defined as the mandatory channel, for the low-band operation, channel 3 is the mandatory channel and for the high-band operation, channel 9 is the mandatory channel. International Journal of Electronics and Electrical Engineering Vol. 2, No. 3, September, 2014 ©2014 Engineering and Technology Publishing 222 doi: 10.12720/ijeee.2.3.222-228