Abstract:

A first work titled “An improved educational software for learning Spread-Spectrum communications over a real acoustic channel using audio hardware” has been submitted to the 10th Annual International Technology, Education and Development Conference (INTED). In the first work, we developed a software tool using MATLAB for learning direct sequence spread-spectrum communications over a real acoustic channel (it ranges until 20Khz). The first work is focused on the software tool and the evaluation of different multiuser scenarios. However, this second work is focused on the hardware used to create the real CDMA (Code Division Multiple Access) multiuser transmission scenario used in the first work. Specifically, we describe how the multiuser scenario has been implemented taking into account both audio hardware and connections/initializations of different audio interfaces. The objective is to create a real CDMA scenario based on sound sources. Specifically, we have developed a CDMA scenario composed of three users. In this manner, each user can simultaneously send information that is transmitted using a speaker associated to a specific user over a real acoustic channel. Audio hardware, such as multichannel audio interface, speakers or microphone, audio software to play multichannel sound sources and its parameters are detailed.

The CDMA multiuser transmission scenario, based on Spread-Spectrum communications, using audio hardware material will be available in one of the laboratories of the Telecommunication Engineering of the University of Jaen. In this way, this second work complement the previously mentioned first work because student can learn not only the concepts related to spread-spectrum communications but also the hardware used to replicate a real CDMA multiuser scenario in which different communications systems and multiuser scenarios can be analysed using software plus audio hardware resources

Keywords:

CDMA, spread-spectrum, audio, hardware, interfaces, multichannel, resources.