Implementation of a Low-Complexity Frame-Start Detection Algorithm for MIMO Systems
ABSTRACT Multiple-input multiple-output (MIMO) communication systems require well-designed synchronization schemes in the receiver to meet stringent QoS requirements. In particular, OFDM modulation is very sensitive to timing synchronization errors, which cause inter-symbol interference. This paper describes a frame-start detection algorithm, which relies on received signal power increase and does not require any special properties of the transmitted signal. The performance is analyzed and then, verified through simulations in a MIMO system employing orthogonal frequency division multiplexing. Finally, a low-complexity FPGA implementation of the presented algorithm is described in detail.
Conference Proceeding: Synchronization and AGC proposal for IEEE 802.11 a burst OFDM systems[show abstract] [hide abstract]
ABSTRACT: Synchronization is critical in the design of an OFDM receiver. Large timing offsets result in a loss of orthogonality between subcarriers, ISI, and severe bit error degradation. To minimize this degradation, standards incorporate preambles intended for all OFDM acquisition functions including automatic gain control (AGC) and synchronization. Several synchronization algorithms have been proposed. Unfortunately, these proposals do not take into account AGC effects which degrade results in practice. To address this problem, we have built an FPGA implementation of both an AGC and synchronization system. Based on these results, in this paper we propose a novel standard compliant auto-correlation synchronization algorithm and AGC interface, then measure the total system performance.Global Telecommunications Conference, 2003. GLOBECOM '03. IEEE; 01/2004
Conference Proceeding: A Frame-Start Detector for a 4×4 MIMO-OFDM System[show abstract] [hide abstract]
ABSTRACT: Future wireless LANs will increase the peak data rate by employing multiple antennas at both transmitter and receiver. Well designed synchronization algorithms are a prerequisite for meeting stringent QoS requirements. In particular OFDM modulation, which constitutes the basics for WLAN, is very sensitive to timing synchronization errors which incur inter-symbol interference. In this paper, a novel frame synchronization algorithm is proposed that is implemented in the FPGA of a real-time MIMO-OFDM testbed. Simulations show it to be of sufficient performance in scenarios of interest, while the hardware complexity is suitable for an FPGA implementation. Additionally, the algorithm exhibits a good resilience against narrow-band interference, which causes problems in traditional frame-start detection algorithmsAcoustics, Speech and Signal Processing, 2006. ICASSP 2006 Proceedings. 2006 IEEE International Conference on; 06/2006 · 4.63 Impact Factor
Conference Proceeding: An automatic gain controller for MIMO-OFDM WLAN systems[show abstract] [hide abstract]
ABSTRACT: MIMO-OFDM based wireless LAN standards are currently being defined. These systems employ packed-based communication, which requires fast and accurate automatic gain control. The precise estimation of the expected receive signal power of data symbols, based on preamble symbols is required in order to optimally detect the data signals. In this paper, two different preamble OFDM-symbols are considered and analyzed with regards to their suitability for received signal power estimation in MIMO-OFDM systems. An AGC architecture for an IEEE 802.11a based MIMO system is proposed and FPGA implementation results are reported.Circuits and Systems for Communications, 2008. ECCSC 2008. 4th European Conference on; 08/2008