A comparative study of STBC transmissions at 2.4 GHz over indoor channels using a 2 × 2 MIMO testbed

Abstract

In this paper we employ a 2 × 2 Multiple‐Input Multiple‐Output (MIMO) hardware platform to evaluate, in realistic indoor scenarios, the performance of different space‐time block coded (STBC) transmissions at 2.4 GHz. In particular, we focus on the Alamouti orthogonal scheme considering two types of channel state information (CSI) estimation: a conventional pilot‐aided supervised technique and a recently proposed blind method based on second‐order statistics (SOS). For comparison purposes, we also evaluate the performance of a Differential (non‐coherent) space‐time block coding (DSTBC). DSTBC schemes have the advantage of not requiring CSI estimation but they incur in a 3 dB loss in performance. The hardware MIMO platform is based on high‐performance signal acquisition and generation boards, each one equipped with a 1 GB memory module that allows the transmission of extremely large data frames. Upconversion to RF is performed by two RF vector signal generators whereas downconversion is carried out with two custom circuits designed from commercial components. All the baseband signal processing is implemented off‐line in MATLAB®, making the MIMO testbed very flexible and easily reconfigurable. Using this platform we compare the performance of the described methods in line‐of‐sight (LOS) and non‐line‐of‐sight (NLOS) indoor scenarios. Copyright © 2007 John Wiley & Sons, Ltd.

MATLAB as a Design and Verification Tool for the Hardware Prototyping of Wireless Communication Systems

“…Indeed, MATLAB plays a key role in off-line testbeds that are used to prototype state-of-the-art MIMO-OFDM systems [9][10][11][12][13].…”

Design, Implementation and Testing of a Real-Time Mobile WiMAX Testbed Featuring MIMO Technology

“…Although we have found in the literature low-bandwidth MIMO testbeds based on the IEEE 802.11n [6] and the 802.16d standard [7], [8] (i.e. no mobility), we have not encountered literature for real-time MIMO testbeds implementing the IEEE 802.16e standard using a 20 MHz bandwidth.…”

A Distributed Multilayer Software Architecture for MIMO Testbeds

“…Throughout this chapter we will focus on testbeds because they use open designs and are more often found in public research centres and academia. Various MIMO testbeds have been reported in the literature (Borkowski et al, 2006;Caban et al, 2006;Fabregas et al, 2006;Haustein et al, 2006;Nieto et al, 2006;Ramírez et al, 2008;Rao et al, 2004;Wilzeck et al, 2006;Zhu & Fitz, 2005). Some of them have been constructed to evaluate a particular standard or specification while others have been designed for general purpose.…”

“…Indeed, there exists few contributions García-Naya et al, 2008a;Rao et al, 2004;Rupp et al, 2007) that contain a detailed description of the constructed MIMO testbed and, except for (García-Naya et al, 2008a;Rupp et al, 2007), the information contained on them is already outdated. Based on the previous experience acquired by the research group of the authors in building and setting up MIMO testbeds, as well as performing indoor measurements Ramírez et al, 2008), we can assert that once the testbed hardware is available and properly configured, accessing the testbed becomes the main and also frequently ignored issue. When a research team decides to start the process of acquiring and/or constructing a new testbed, they need to take into account numerous aspects related both with the hardware and its technical features, and the extensibility possibilities for the future (García-Naya et al, 2008a;Rupp et al, 2007).…”

“…This architecture enables the testbed to be easily accessible by the researchers and to be integrated in the development environment they are using. Although all designs and results herein presented are particularized for our MIMO testbed (García-Naya et al, 2008b;Ramírez et al, 2008), they are easily adaptable to most of the existing testbeds, making even possible the integration of heterogeneous testbed nodes in order to build a multi-terminal testbed. The proposed software architecture consists of three different layers:…”