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IntroductionWireless Body Area Network (WBAN) is a cluster of wireless sensors worn by humans mainly for the purpose of medical condition monitoring. The human physiological data such as blood pressure or body temperature are monitored by the sensors and sent to a data processor regardless of the location or the activity of the subject [1]. WBAN is a structure which contains a short-range communication system based on IEEE 802.15.6. The standard allows for lowpower and small-sized devices and includes characterization of electromagnetic wave propagation transmitted by a device located on or in the human body.Aside from being able to send information using a small-sized antenna and limited power, a WBAN device must also be able to send information reliably over a long term. Reliability and durability can be achieved through appropriate modulation and coding schemes. The modulation scheme choice will affect the transmitter and receiver power required by WBAN device, which will subsequently affect the device lifetime. However to achieve high reliability, the coding scheme will play the more important part compared to that of the modulation scheme. An ideal coding scheme for WBAN is one that ensures reliable transmission of information in a rapidly changing wireless channel.Raptor codes, an extension of Luby-Transform (LT) codes with linear time encoding and decoding have been shown to attain good upper-bound on overall error probability when used in binary erasure channel [2]. Several channel model for WBAN has been proposed based on numerical simulations and/or measurements. A mathematical model using dyadic Green function to model the human body as a simplified cylinder has been proposed and used to show the receive signal variations around the human body [3]. Another research proposes the use of pathloss channel model based on measurement [4]- [5]. The pathloss channel is stated as a function of distance and frequency, and the fluctuating power is shown to match lognormal distribution. As the wearer of a WBAN device moves around, the wireless channel is subject to fading. Objects around the human body will also reflect and scatter the signal, contributing to a multipath fading of a Rice distribution [6]. A more general fading model form WBAN is Rayleighdistributed. Another possibility that can be taken into consideration is the Nakagami-m distributed fading channel, as this is the model which provides indoor-mobile multipath propagation in addition to ionospheric radio link [6]. Various researches have shown that Raptor codes provide a robust data transmission even in noisy channels. The performance of an optimized Raptor code in quasi-static Rayleigh fading channel has been analyzed and shown to

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