Bit error rate simulation studies for PSSS with multi-user detection for industrial multipath-fading environments

Wireless connectivity offers industrial automation the flexibility, mobility and reconfigurability it requires to cope with the new challenges of industry 4.0. Communication in industrial applications like factory automation (e. g. closed-loop control) imposes ambitious demands on wireless communication systems as these applications require very low latencies at ultra-high reliabilities. Additionally, the industrial environment encourages harsh channel conditions due to numerous metallic reflectors in typical factory halls. Since state of the art wireless technologies are not able to completely fulfill these requirements especially in industrial wireless channels, novel approaches are being developed. In that regard, Parallel Sequence Spread Spectrum (PSSS) transmission is seen as a promising technology as it allows transmission with very short latencies. Nevertheless, its bit error rate performance has not yet been analyzed for typical industrial wireless channels. This paper presents a PSSS system concept and two associated receiver structures which might be suitable for the targeted applications. A detailed mathematical description of the transmission of the PSSS signal in an additive white Gaussian noise channel and a time-dispersive channel is given. The performance of the system approach is analysed in industrial multipath-fading channels. Simulations show that the bit error rate curves of both receiver structures under consideration vary enormously for the considered channels. It can be shown that a multi-user detection receiver achieves better BER results than a single-user matched filter, but further ways of improvement need to be analysed.

I. Introduction

Nowadays, modern wireline fieldbuses are used for industrial communication. On the one hand, they provide very low latencies and high reliabilities in combination with a deterministic behaviour. On the other hand, they have limitations in flexibility, support of mobility and reconfigurability. Future industrial automation systems require a maximum degree of flexibility, mobility and reconfigurability as well as they need to be highly interconnected. This can only be enabled with wireless communication.