Using multiple channels to improve SDR flexibility and performance

Software Defined Radios (SDR) emerged as an alternative approach to provide adaptable wireless communication capacity. Instead of providing specific hardware interfaces for any communication standard, it provides a generic physical layer that together with a software part is able to reproduce several communication standards. A typical drawback of SDRs is the high coupling between the software and the hardware layers, which makes hard to migrate the software part to different hardware without modifications. To overcome this problem, this paper presents a flexible architecture for SDRs that is based on the well-know channel concept. By using multiple channels the proposed architecture is able to abstract the interface of any SDR hardware, so that it becomes easy to make hardware modifications. The paper also presents a hardware implementation for our proposed multiple channel system, which shows a considerable performance improvement compared to a typical solution. To prove our concept we implemented the proposed architecture using the GNU Radio framework and performed experiments running the same application on different hardware (USRP, USRP2, and a modified USRP2). The results from such experiments are presented and discussed along the paper.