WBAN Transceiver Design

Abstract

The tremendous progress in wireless medical and health care applications in recent years, as well as the significant improvements in wireless communication and semiconductor technologies, led to the rapid development in the wireless body area networks (WBAN) technologies [1,2], which can be used to connected the PBS and SIDs in the wireless medical/health care systems as shown in Chap. 2. Frequency Bands for WBAN TransceiversThe IEEE 802.15.6 WBAN standard was released by the IEEE LAN/MAN standards committee for the short-range low-power WBAN operated on, in, or around the human body (but not limited to humans) in February, 2012 [3]. The standard physical (PHY) layer defines a narrow band (NB) mode compliant device (hub/node, corresponding to PBS/SID in the application systems) shall be able to support at least one of the following frequency bands: 402-405, 420-450, 863-870, 902-928, 950-958, 2,360-2,400, and 2,400-2,483.5 MHz. Before the 802.15.6 standard was released, IEEE 802.15.4/ZigBee low-rate wireless personal area network (LR-WPAN) standard was also widely used for WBAN devices [4]. The IEEE 802.15.4 standard PHY layer defines its operation on one of the three possible unlicensed frequency bands: 868, 902-928, and 2,400-2,483.5 MHz [5]. In some occasions, the below VHF band is used for WBAN, including 6.78 MHz, 13.56 MHz, 27.15 MHz, and 9-315 kHz for inductive link.The frequency available for WBAN in 400 MHz UHF, 2.4 GHz ISM and UWB bands for different countries and areas are illustrated in Fig. 4.1 [6].Note that in real applications, only the 400 MHz and 2.4 GHz bands are most commonly used for the wireless medical and health care applications, since the 400 MHz band signal has small through-body transmission loss, and the There are three types of wireless communications in WBAN as mentioned below:1. In the body: SID inside human body, PBS outside body 2. On the body: SID and PBS attached to the body 3. Around the body: SID attached to body, PBS near the body Whether to use the 400 MHz band or the 2.4 GHz band depends on the real application conditions. To satisfy the miniaturization and low energy consumption requirements of the different WBAN applications, in-body and on/around-body SIDs (nodes) usually work on different communication frequencies. High frequency helps to reduce the antenna size, and the on/around-body nodes are usually designed in 2.4 GHz band to make their dimensions acceptable. However, the 2.4 GHz electromagnetic wave shows more propagation attenuation through the body tissue than the 400 MHz wave. In some applications, it is a good choice to choose 400 MHz band for in-body nodes to minimize the power consumption. Thanks to the high relative permittivity of the body tissue, which is about 30~60 in different tissues. The antenna of in-body nodes still can be designed in small dimensions. The comparison of the 400 MHz band and the 2.4 GHz band is shown in Table 4.1. Previously reported wireless transceivers for WBAN PBS (hubs) only focused on the 400 MHz or the 2.4 GHz single band op...