Simulation/Emulation Environments

In addition to real-time operation, the OpenAir development effort can be used to implement several different forms of simulators. In the following sections, these are briefly described.

Algorithmic and performance simulation

Most signal processing routines are provided in un-optimized C code to aid in functional verification of the algorithms. In some instances SystemC models for signal processing functions are also provided for functional simulation of an embedded SoC design. Optimized C code for Intel architectures (using MMX/SSE/SSE2 intrinsics) can be used for efficient numerical performance evaluation. To this end, optimized routines for random number generation are also provided.   Use of these routines for performance evaluation is explained on the OpenAirInterface Twiki site.

Ethernet-based Functional Emulators

An emulation enviroment for functional validation of the implementation is provided. This makes use of a mini-cluster of PCs which exchange signals or MAC data units over an ethernet network (using IP-multicast as a transfer medium). This mimics a real radio environment to different degrees of precision and uses the same C code as the software-radio implementation. A non real-time emulation of the RF environment and data acquisition mechanisms (RF behavioral simulation) exchanges complex baseband signals between nodes in the network and all protocol layers are executed. The RF behavioral simulator is under development and will be released shortly. The real-time emulator, under the RTAI RTOS (www.rtai.org) exchanges MAC data units between nodes in the network and the physical layer is simulated using a behvioral abstraction model. The behavioral PHY abstraction model is under development, but the real-time mechanism for MAC/IP emulation is currently available.

An overview of our emulation methodology can be found here.

SoC development simulation platform (PHY/MAC)

A simulation platform for a HW/SW co-designs is also being developed. This makes use of the LEON3 open-source tool suite by Gaisler Research (www.gaisler.com).  This will be progressively made available in the public-domain as part of openair0 which contains all our current harware development for CardBus MIMO I and ExpressMIMO.