VICASSO: a new flexible base-band transceiver ASIC for a wide range of DSSS communication applications

Direct sequence spread spectrum (DSSS) modulations have been widely used in different application fields over the past few years. Their main assets are now well known : reliability, robustness, communication privacy. The main drawback is a low spectrum efficiency due to spectrum spreading. This paper addresses a new base-band transceiver dedicated to point to point DSSS communications. This ASIC called VICASSO (Versatile Integrated Circuit for Advanced Spread Spectrum mOdulations) can be configured in many ways to suit a broad range of applications. First, in order to improve spectrum efficiency, M-ary orthogonal keying (MOK) and multi codes (MC) techniques have been implemented. Then, to face out inter symbol interference (ISI), a code hopping (CH) technique has been used. Many configurations mixing these modulations are available leading to a very flexible approach. VICASSO enables the end user to choose the best trade-off between data rate, robustness and spectrum efficiency for a given application. The functional description of the ASIC, its hardware features and its performance are detailed in this paper