While GPS high quality products supplied by leading global components (Motorola, Analog Devices, Sirf, Maxim, Qualcomm ...) are available, many research works are carried out in order to improve sensitivity, response time, dynamics, accuracy, size and power consumption. In addition, continuity of the positioning service between outdoor and indoor appears as a must for the next years. Most of the receivers are limited to a single standard and do not offer positioning services in areas where satellites are not available. Although many techniques have been proposed these last ten years, ranging from High-Sensitivity GNSS (Global Navigation Satellite System) to sensor networks, through Assisted-GNSS or WLAN based approaches, no ultimate solution seems yet to provide the answer to the indoor positioning problem, probably crucial to Location Based Services. In order to enhance receiver performance in harsh environments where significant multipath problems are present and ensure continuity of the positioning service between outdoor and indoor, digital receiver processing (Acquisition and tracking) could benefit from the use of different RF bands in GNSS systems. Hence, implementing multiband GNSS receiver in mobile equipment can be considered as a promising solution in the navigation domain. We propose then to design a multistandard GNSS receiver including the GPS L1, L2 and L5 bands [1], the GLONASS G1 band [2] and also the Galileo E1 and E5 bands [3]. To the authors knowledge, only one chip, the MAX2769 [4], addresses this three systems but does not include a digital stage for data signal processing. Proposed architecture, in this work, is based on an RF subsampling down-conversion topology [5]. A fixed subsampling frequency is chosen to properly down-convert the three constellations RF bands to a fixed IF band, which relaxes the IF filter design. A Direct Digital Converter is designed to perform quadrature down-conversion to baseband. The front-end design takes into account the main requirements implied by the indoor positioning methods [6]. Hence, the proposed architecture can implement in the digital stage GNSS approaches for indoor positioning, as described in previous papers [7], and [ 8] for the associated multipath problem in indoor environments. The design methodology of this innovative GPS/GLONASS/GALILEO receiver architecture providing outdoor to indoor positioning service is fully described by authors in previous work [9]. In the present paper, we propose to study the GNSS RF-Front-End prototype based on commercial components and validate the total gain and noise factor of the chain by RF simulation, and the BER by RF/DSP co-simulation