Improved Receiver Design for WBAN Employing UWB Based Mimo Scheme

摘要

Wireless sensor networks built in or around the human body are known as Wireless Body area networks (WBAN). Body area network has its own standard IEEE 802.15.6. They can be adapted for patient monitoring applications. The biological sensors are either implanted or placed on the human body. They measure vital information such as ECG, Blood pressure etc. and transmit them wirelessly to a nearby gateway. Transmission of patient’s health information is done using digital communication system. Due to time dispersive nature of communication channel, the transmitted data gets distorted and as there are multiple wireless devices on the human body, multiple access interference occurs. This leads to need for equalizers at the receiver end. Incorporating suitable equalization technique, makes the receiver design a challenge. Ultra wideband (UWB) communication with its strong advantages has proved to be very promising for WBAN applications. It is a low power high data rate technology. They have potentially low complexity and low equipment cost. Similarly, Multiple Input Multiple Output (MIMO) systems have emerged as a promising technology to increase the data transmission rate, improving link reliability and enhancing the system coverage. Hence, in this work we have considered a WBAN system employing UWB based MIMO scheme. Another important aspect is that robustness of a particular MIMO system against multipath channel fading and division among users, depends on orthogonality of the spreading codes. Hence, Orthogonal complete complementary code has been used as the spread code. The research aims at finding the most suitable modulation format for transmission of medical signals for the proposed system model through BER performance analysis. The prime goal is to enhance the performance UWB (Ultra Wideband) / MIMO (Multiple Input Multiple Output) (2X2) WBAN system employing Orthogonal Complete Complementary (OCC) code as the spread code. Simulation results have been obtained to validate the improvement in the performance of the system in terms of Bit Error Rate (BER).