Experimental evaluation of UWB wireless communication within PC case

Abstract

A novel concept of the use of an ultra-wide bandwidth (UWB) ultrasmall-scale wireless interconnect scheme inside an electrically small enclosure is proposed. The concept is presented using a PC tower case as a model environment in which a channel measurement campaign has been made with two different types of antennas. Ricean K factor analysis was conducted for different positions of the antennas to identify the multipath behaviour of the channel, as well as channel capacity. An average maximum channel capacity of almost 6 Gbit/s is achieved using the whole UWB band for one of the antennas, assuming a signal-to-noise ratio of 25 dB. This work supports the proposal that a high-capacity UWB wireless interconnect scheme for communicating different devices within a PC case scenario may be used to replace wired interconnections, providing a wireless backplane system.Introduction: Look inside a conventional PC enclosure and one sees a big range of cables and line buses connecting different components. Part of these cables connects the main board (MB) to devices such as CD-ROM or floppy disk. These wired buses have a maximum data rate of no more than 3 Gbit/s using the serial advanced technology attachment (SATA II) with future improvements [1]. If we look closer we can find another type of thin cable integrated in different boards, such as the MB or peripheral cards (PCBs), interconnecting different microchips of their own substrate, where the standard data rate for a 32-bit communication will not exceed 1 Gbit/s [2]. All these interconnections require a huge amount of space, where further improvements of data rate would be limited by this fixed architecture. Replacing part of these wired cables inside small cavities has become an important future technology receiving increasing research interest [3]. We propose in this study to substitute the wired bus connections by small antennas, in order to enable a wireless interconnect between components. This study is based in the ultra-wide band (UWB, 3 -11 GHz) [4]. However we ignore FCC power regulations owing to the considerable effort expended in the electromagnetic compatibility field in ensuring that equipment enclosures do not permit radiation to leak out. The use of the UWB band is vital to achieve the highest data rates possible to match SATA II or PCI bus technologies.

An approach to ultra-wideband channel calibration using a vector network analyser

“…Whereas this was useful, they do not indicate how the calibration was achieved, nor do they provide the reasons for the adopted calibration technique. Other researchers have measured certain UWB channels, however they have not explained whether a calibration process was in fact used at all (Bellens et al, 2009;Donlan et al, 2006;Katayama et al, 2006;Keignart and Daniele, 2002;Kobayashi, 2006;Nakahata et al, 2008;Nkakanou et al, 2011a;Nkakanou et al, 2011b;Bieder et al, Dec.2006;Abbasi et al, 2011;Gelabert et al, 2011;Elmansouri and Filipovic, 2011;Chen et al, 2009). …”

Adaptive OFDM for Wireless Interconnect in Confined Enclosures

“…The UWB wireless channels in computer chassis have been studied extensively by numerous authors [5] - [8]. To our best knowledge, the implementation of such a link has only been explored by Intel Corp. e.g.…”

“…It is expected to replace the wired bus systems [1] - [5]. The benefits are: reduction of latency, chip/printed circuit board area, and electromagnetic interference; simplification of architectures; and increased flexibility of the architecture [1] - [5].…”

“…The candidate technologies are Ultrawideband (UWB) [1] - [3], [5], mm-Waves (60 GHz) [1] - [4], sub-THz [2], and THz technologies [2]. mm-Waves, sub-THz, and THz technologies offer significantly higher data-rates and are reported to be more energy efficient than UWB [1], [2], [4], but they have a limited range.…”

“…The advantage of UWB communication links, is the fact that they can service links with ranges in the >10 cm range even for the NLOS case [1], [5]. Thus for wireless links transferring data between more distant components, e.g.…”