Lime Micro Opens Orders for the LimeSDR XTRX, an Open-Hardware mPCIe Software Defined Radio

Lime Microsystems has opened orders for the LimeSDR XTRX, a high-performance open-source software defined radio (SDR) in a mini-PCI Express (mPCIe) form factor.

Designed as successor to the discontinued Fairwaves XTRX, the LimeSDR XTRX can act as a drop-in replacement in existing projects and designs – complete with full compatibility with the legacy Fairwaves driver and software stack – while also offering a range of improvements over the original, thanks to a complete redesign.

The LimeSDR XTRX is a fully open-source project, with the hardware designs and firmware source released under the permissive Solderpad Hardware License v2.0. In addition to support under legacy Fairwaves driver, the LimeSDR XTRX is also compatible with the actively-developed Lime Suite driver and application programming interface (API) – as used by other devices in the LimeSDR family, including the LimeSDR Mini 2.0.

Built around Lime Micro’s high-performance LMS7002M field-programmable radio-frequency chip, the LimeSDR XTRX offers two full-duplex multiple-input multiple-output (MIMO) channels with a frequency range of 30 MHz up to 3.8 GHz and a bandwidth of 120 MHz. It can sample at a 12-bit depth and a rate of 120 MSPS SISO / 90 MSPS MIMO, and transmit at up to 10 dBm depending on transmission frequency.

The LMS7002M is supported by an AMD Xilinx Artix 7 field-programmable gate array (FPGA), offering 52k look-up tables (LUTs), 120 18×18-bit multipliers, five phase-locked loops (PLLs) and four delay-locked loops (DLLs). Its spare logic capacity, coupled with the open-source gateware provided by Lime Micro, provides opportunity for defining new functionality on-device – offloading signal processing or detection from the host device, for example.

The LimeSDR XTRX board is designed to be used in a mPCIe socket, though it can also be used externally via a micro-USB socket – giving it compatibility with a wide range of host systems, from low-power embedded devices like Raspberry Pi single-board computers and the Raspberry Pi Compute Module family to high-performance servers and more.

“We are thrilled to be adding the LimeSDR XTRX to the LimeSDR family of open-hardware software-defined radios,” says Lime Micro chief executive officer Ebrahim Bushehri. “Fairwave’s original design had a lasting impact on the software defined radio ecosystem, and we are honoured to be able to continue that legacy while updating the platform for users new and old.”

The LimeSDR XTRX is available to pre-order now via Crowd Supply at $699 at the launch of a six-week crowdfunding campaign, with hardware expected to begin shipping to backers in late November. More information on the LimeSDR XTRX’s improvements over the original to be published as the campaign progresses.