High Performance Software Defined Radio - HPSDR

1. Generalities

HPSDR (High performance software defined radio) is a project that is currently under development by a group of radio amators enthusiasts. This project aims to developed the different blocks that constitues a radio. Each module is designed by a group of person and can be connected to others modules thanks to a common bus. Assembling a HDSDR radio can be seen as plugging cards into a motherboard.

From a user point of view, no product that directly runs is avaible. The user has to select its own modules and to assemble its own radio. This solution is then addressed to people with some knowledge about radios.

2. Main characteristics

As mentionned above, the HPSDR aims to develop modules that are then choosed and assembled by an experimented user. Hence many radios can be built, resulting from many board combinaisons. So in this section, we describe the main characteristics of a radio close to alternative solutions (USRP and SSRP). Note that this radio is only a receiver:

Radio interface to computer	It is connected to a computer with a USB 2.0 interface. Because of this interface, it is limited to signals with at most 5 MHz of bandwidth.
Frequencies	No RF, it only only works in 0-60MHz
MIMO	No
ADC/DAC	ADC: 16 bits - no DAC
Baseband	The baseband processing consists in sampling the signal and performing the downconvertion.
Software	???

3. Some modules

A few examples are given to illustrate the HPSDR project. Note all modules are not listed in this page.

3.1. The Atlas Module

This module is the backplane. It is simply the card where all modules are plugged.

3.2. The Janus Module

The Janus module is a very high performance, dual, full duplex, A/D and D/A converter board. The A/D sample rate options are 48, 96 or 192kHz and the D/As are fixed at 48kHz. These rate are compatible with narrow band communication signals.

3.3. The OZY Module

This module makes the link between the HPSDR and a computer through and USB 2.0 link.

3.4. The Mercury Module

The Mercury module is the RF module of the HPSDR, since it enables direct sampling of the 0-65 MHz spectrum. Based on a Linear Technology LTC2208 130MSPS 16-bit A/D converter, the board will contain it's own FPGA to undertake Digital Down Conversion (DDC) to 250 kSPS or less for transfer over the Atlas bus to the USB interface on the OZY board.

4. See also

• Official website of HPSDR