Regular paper IEEE 802.15.6 WBAN Standard Compliant IR-UWB Time-Hopping PPM Transmitter using SRRC signaling pulse Babita Jajodia a,⇑ , Anil Mahanta b , Shaik Rafi Ahamed b a Department of Electronics and Communication Engineering, Indian Institute of Information Technology Guwahati, Bongara, Guwahati 781 015, India b Department of Electronics and Electrical Engineering, Indian Institute of Technology Guwahati, Guwahati 781 039, India article info Article history: Received 19 June 2019 Accepted 4 February 2020 Keywords: IEEE 802.15.6 Impulse-Radio (IR) Square Root Raised Cosine (SRRC) Time-Hopping Pulse Position Modulation (TH-PPM) Ultra-Wideband (UWB) Wireless Body Area Networks (WBAN) abstract This paper develops the design of an IEEE 802.15.6 Impulse-Radio (IR) Ultra-Wideband (UWB) transmit- ter for Wireless Body Area Networks (WBAN) in 180-nm CMOS technology. The transmitter operates at the mandatory data rate of 0.487 Mbps and employs a pulse position controller (PPC) to place the Square Root Raised Cosine (SRRC) pulse for a time-hopping pulse position modulation (TH-PPM) scheme. This transmitter features a novel piece-wise linear approximation (PWLA) approach for generation of SRRC signaling pulse. It is found that the generated PWLA SRRC pulse is fully compliant with the WBAN spec- tral mask. The proposed PWLA approach has the potential to approximate an arbitrary signaling wave- form with a high degree of accuracy and hence should be useful in transceiver realizations. Ó 2020 Elsevier GmbH. All rights reserved. 1. Introduction According to the statistics of World Health Organization (WHO), the elderly people are the fastest growing age group worldwide [1]. By 2050, two billion people or nearly one out of every four people will be older than 60 years. Migration is one of the changing social dynamics affecting the care and well-being of older people as fami- lies get smaller and younger family members move away or go abroad [1]. As people age, they are more likely to have mobility dif- ficulties and suffer chronic ailments. At the global level, there is an increasing trend in occurrence of chronic diseases among people of all ages. This can be controlled by active wellness management and by early diagnosis and detection before it is too late [2,3]. Increasing access to medical and assisting devices without affecting the normal life of a person is thus desirable. The need for health-care systems using the technological advancements in wireless commu- nications has witnessed the design of low-power, intelligent and miniaturized invasive/non-invasive medical devices to be used on or around the human body or implanted in human body for constant health monitoring and advice [4,3]. This special type of wireless sen- sor networks (WSN) are referred to as Wireless Body Area Networks (WBAN). The design of an efficient, low-power transceiver architec- ture is thus of utmost importance for WBAN nodes [5–14]. The IEEE 802.15.6 [16,15] is an international standard for low power, short range and extremely reliable wireless communication within the surrounding area of the human body supporting three physical layers (PHYs), namely, narrowband (NB) PHY, ultra Wide- band (UWB) PHY and human-body communications (HBC) PHY. The standard specifies a mandatory PHY for the default mode of operation that employs Impulse-radio (IR) UWB communications. The shape of a pulse is of utmost importance in an IR-UWB transceiver system as it dictates the frequency spectrum of the transmitted signal. It is necessary to design an IR-UWB pulse gen- erator, a key component of the transmitter, that produces an accu- rate pulse shape and follows the mandatory Federal Communications Commission (FCC) spectral mask [17]. IR-UWB pulse generators can be classified into two categories:  Carrier-less UWB waveform encompassing a bandwidth of f min (P3.1 GHz) to f max (610.6 GHz) and conforming to FCC spectral mask [17].  Carrier-modulated (multi-band) UWB waveform conforming to the definition: a signal of bandwidth P500 MHz modulating a carrier frequency f c , where 3.1 GHz 6f c 610.6 GHz, such that the transmit power spectral density (PSD) satisfies the FCC mask. Some of the classical IR-UWB pulse generators belonging to the first category are: (i) LC oscillator-switching technique [18] (ii) filter-excitation technique [19] (iii) digital pulse-shaping https://doi.org/10.1016/j.aeue.2020.153119 1434-8411/Ó 2020 Elsevier GmbH. All rights reserved. ⇑ Corresponding author. E-mail address: babita@iitg.ac.in (B. Jajodia). Int. J. Electron. Commun. (AEÜ) 117 (2020) 153119 Contents lists available at ScienceDirect International Journal of Electronics and Communications (AEÜ) journal homepage: www.elsevier.com/locate/aeue