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A novel method for distance estimation is introduced, based on an OFDM signal combined with the Zadoff-Chu Sequences. By exploiting the properties of these sequences it is possible to evaluate the distance between a transmitter and a receiver with a very good precision and accuracy. The technique effectiveness is demonstrated in a real operating environment by measuring the distance between two active...
In the scenario of multiple access communication, the spectral sidelobes and peak-to-average power radio (PAPR) problems of orthogonal frequency division multiplexing (OFDM) must not be ignored. This paper proposes a novel precoding scheme that ahead of inverse discrete Fourier transformation (IDFT) is presented to jointly suppress the in-band-out-of-subband (IBOSB) radiation and high PAPR in orthogonal...
Sparse channel estimation (SCE) in orthogonal frequency division multiplexing (OFDM) systems with large number of virtual sub-carriers and regularly spaced pilots is studied in this paper. Such OFDM systems are present in wireless standards like long term evolution (LTE). We numerically evaluate the performance of popular compressive sensing (CS) algorithms and shows that low complexity CS algorithms...
A novel family of quadrature amplitude modulation (QAM) Golay complementary sequences (GCSs), in this paper, is presented. The resultant QAM GCSs employ binary signals rather than quaternary signals as their inputs. New sequences are fit for being applied to such QAM systems whose inputs merely are binary signals. In addition, the proposed sequences have the larger family size than the previously-known...
Based on the description Q-type-2 of quadrature amplitude modulation (QAM) constellation and standard Golay-Davis-Jedwab (GDJ) quaternary complementary sequences (CSs), this paper presents a new family of QAM Golay complementary sequences (GCSs), and determines their family size. The proposed QAM GCSs includes the known QAM GCSs from Cases I–III constructions as a special case. It is worthy of mentioning...
This communication addresses the problem of the recognition systems based on OFDM (Orthogonal Frequency-Division Multiplexing). Such a problem arises in various fields of applications among cognitive radio and military applications. We present a new blind discrimination algorithm between the standards: the 3GPP/LTE (3rd Generation Partnership Project/Long Term Evolution, the WiMax IEEE 802.16 (Worldwide...
Linear pilot-aided channel estimation in orthogonal-frequency division multiplexing (OFDM) systems is carried out optimally via 2D Wiener filters. The standard approach employed in conventional receivers is based on cascaded 2×1D Wiener filtering, which has a lower complexity but also suboptimal performance. The 2D+1D filtering scheme proposed in this paper combines the benefits of the two other schemes...
Narrowband power line communications (NB-PLC) operating in the 3–500 kHz frequency band is proposed as a solution to support the emerging Smart Grid applications that aim to optimize the efficiency and reliability of the power grids. PLC is attractive for Smart Grid communications as it can be deployed over the existing power grids without any additional infrastructure. However, PLC suffers from impulsive...
In this paper, we design an improved transmission parameter signaling scheme that provides a higher quality of reception compared to the conventional P1 preamble of DVB-T2 systems. Specifically, we utilize the cross-correlation properties of the discrete Fourier transform (DFT)-spread Chu sequences. Simulation results show that the proposed signaling scheme has better signaling error rate (SER) performance...
This paper applies a recently proposed efficient technique that has been conducted regarding timing synchronization in OFDM systems, to the IEEE 802.11a/g standards. The time synchronization is fulfilled using the structure specificity of the short training sequence of IEEE 802.11a/g preamble. Two versions of the applied technique are considered: a singlestage brute force approach, which carries differential...
In this paper, we propose to study the spectrum awareness also called classification of various signals enabling the OFDM-based cognitive radio systems (CRS). In order to do so, some key properties relevant to the detection of the OFDM-based third-Generation Partnership Project Long Term Evolution (3GPP LTE) and digital video broadcast for terrestrial TV (DVB-T) signals as well as programme-making...
Cognitive Radio requires the architecture of radio systems to combine reception and spectrum monitoring functionality efficiently. We propose a flexible digital front end that supports concurrent synchronization and sensing of high-throughput wireless standards. The chip is implemented in 65 nm CMOS technology resulting in a chip area of 6.4 mm2. Fine grain clock gating allows synchronization at 4...
TV white space (TVWS) has been considered a favorable spectrum for sharing with other spectrum deficient technologies. There are three popular TV standards in China: the Digital Terrestrial Multimedia Broadcast (DTMB), China Multimedia Mobile Broadcasting (CMMB) and PAL-D/K (Phase Alternating Line -D/K). In this paper we present a prototype platform for experimental spectrum sensing, which is developed...
This paper presents a flexible architecture suitable for concurrent processing of multiple radio standards. The proposed architecture is based on a coarse-grained reconfigurable cell array, consisting of distinct processing and memory cells. Flexibility of the architecture is demonstrated by performing a coarse time synchronization and fractional frequency offset estimation for multiple OFDM standards...
Various terrestrial digital television broadcasting standards have been developed in the last two decades for both fixed residential and mobile receivers. Since personal mobile terminal integrated with multiple functionalities is becoming more popular, it is highly desirable to come up with a universal platform for mobile TV reception which can detect the system parameters of DTV signals automatically...
In this paper, we present an analysis of different channel estimator structures that can be used and efficiently implemented with minor configuration changes of a common hardware for both LTE and DVB-H. Such common estimator structures for LTE and DVB-H allow algorithm and hardware reuse when both standards are implemented on the same platform. In this approach, a core estimator will be utilized to...
In the cognitive radio context, sensing process is a crucial task. The cognitive devise has to be able to detect and to identify several radio systems. As more standards are now based on OFDM modulation the paper aims with the parameters estimation of such a modulation. All actual OFDM-based standards differ from their subcarrier spacing therefore it will be ingenious to focus on this parameter to...
Orthogonal frequency division multiplexing (OFDM) is the modulation scheme of choice for digital video broadcasting-handheld (DVB-H), which is required to operate under high mobility conditions resulting in significant Inter-carrier Interference (ICI). To mitigate ICI, several cancellation schemes have been proposed but they require reliable channel information at the receiver which is quite challenging...
Orthogonal frequency division multiplexing (OFDM) is the modulation scheme of choice for digital video broadcasting-handheld (DVB-H) which is required to operate under high mobility conditions resulting in significant Inter-Carrier Interference (ICI). Under these conditions, the conventional one-tap per subcarrier channel estimation and equalization is suboptimal since it does not account for ICI...
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