Topic
SC-FDE
About: SC-FDE is a research topic. Over the lifetime, 438 publications have been published within this topic receiving 7547 citations.
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Patent•
22 Mar 2013
TL;DR: In this paper, a phase noise suppression method under the low-complexity channel estimation of an SC-FDE (single carrier-frequency domain equalization) system was proposed, which comprises the following steps of: forming a training sequence by virtue of special characters, obtaining the responses of a small amount of frequency points of CFR (crest factor reduction) and a CIR (channel impulse response) according to the received signal.
Abstract: The invention discloses a phase noise suppression method under the low-complexity channel estimation of an SC-FDE (single carrier-frequency domain equalization) system. The phase noise suppression method comprises the following steps of: forming a training sequence by virtue of special characters, obtaining the responses of a small amount of frequency points of CFR (crest factor reduction) and a CIR (channel impulse response) by virtue of a LS (least square) algorithm according to the received signal, obtaining the initial CFR influenced by a phase noise CPE (common phase error) via a discrete Fourier transform interpolation filter, and performing time-domain noise power estimation and frequency-domain noise power estimation according to the training sequence; after an established channel is obtained, extracting the effective order of the CIR in a time domain, and calculating the copy of the special character received signal; using special characters as cyclic prefixes of transmission data blocks, estimating the ratio of the CPE on one cyclic prefix to the CPE in the initial established channel by virtue of an MMSE (minimum mean square error) algorithm, and then obtaining the ratio of the CPE of the whole data block to the CPE in the initial established channel via linear interpolation; and finally multiplying the CPE ratio with the initial CIR influenced by the phase noise CPE to track the whole channel of the present data block, and suppressing phase noise interference via the frequency-domain MMSE equalization. The channel estimation algorithm disclosed by the invention is low in complexity, thus reducing the complexity of a phase noise suppression algorithm.
TL;DR: In this article, a common phase offset (CPO) tracking in frequency domain is proposed to track CPO, constant amplitude zero autocorrelation code sequence as training sequence is adopted.
Abstract: Frequency domain equalization is the most promising technology that has relatively low complexity in multipath channel. A frame of single carrier system with frequency domain equalization (SC-FDE) has cyclic prefix to mitigate effect of delay spread. After synchronization and equalization procedure on the SC-FDE system, common phase offset (CPO) that can introduce performance degradation caused by phase mismatch between transmitter and receiver oscillators is remained. In this paper, common phase offset tracking in frequency domain is proposed. To track CPO, constant amplitude zero autocorrelation code sequence as training sequence is adopted. By using numerical results, performance of mean square error is evaluated. The results show that MSE of CPO has similar performance compare to the time-domain estimation and there is no need of domain conversion.
Dissertation•
01 Sep 2014
TL;DR: This thesis considers the use of FTN signaling for the uplink of broadband wireless systems employing SC-FDE based on the Iterative Block with Decision Feedback Equalization (IB-DFE) receiver with a simple scheduled access Hybrid Automatic Repeat reQuest (H-ARQ) specially designed taking into account the characteristics ofFTN signals.
Abstract: In a wireless broadband context, multi-path dispersive channels can severely affect data communication of Mobile Terminals (MTs) uplink. Single Carrier with Frequency-Domain Equalization (SC-FDE) has been proposed to deal with highly dispersive channels for the uplink of broadband wireless systems. However, current systems rely on older assumptions of the Nyquist theorem and assume that a system needs a minimum bandwidth 2W per MT. Faster-Than-Nyquist (FTN) assumes that it is possible to employ a bandwidth as low as 0.802 of the original Nyquist bandwidth with minimum loss despite this, the current literature has only proposed complex receivers for a simple characterization of the wireless channel. Furthermore, the uplink of SC-FDE can be severely affected by a deep-fade and or poor channel conditions; to cope with such difficulties Diversity Combining (DC) Hybrid ARQ (H-ARQ) is a viable technique, since it combines the several packet copies sent by a MT to create reliable packet symbols at the receiver. In this thesis we consider the use of FTN signaling for the uplink of broadband wireless systems employing SC-FDE based on the Iterative Block with Decision Feedback Equalization (IB-DFE) receiver with a simple scheduled access Hybrid Automatic Repeat reQuest (H-ARQ) specially designed taking into account the characteristics of FTN signals. This approach achieves a better performance than Nyquist signaling by taking advantage of the additional bandwidth employed of a root-raised cosine pulse for additional diversity. Alongside a Packet Error Rate (PER) analytical model, simulation results show that
01 Jan 2008
TL;DR: A robust transmit beamformer which can successfully tolerate CSI imperfection is proposed which is application of the robust beamforming in the context of downlink MU-SC transmission.
Abstract: We address the problem of transmit beamforming under channel uncertainty for a multiuser (MU), single carrier frequency domain equalization multiple input multiple output (SC-FDE-MIMO) system. SC-FDE-MIMO scheme is effective solution with relative low complexity to combat inter -symbol interference (ISI) whilst exploiting multi antennas diversity gain. In our system, the signal to leakage ratio (SLR) criterion is used to design the transmit beamformer and the minimum mean square error (MMSE) criterion is employed for the receiver equalization and combining. Non-robust beamforming techniques require perfect channel state information (CSI) knowledge which is not available in practice. In this paper, we propose a robust transmit beamformer which can successfully tolerate CSI imperfection. Diagonal loading is employed to introduce robustness to channel state information errors. The novelty of this work, however, is the application of the robust beamforming in the context of downlink MU-SC transmission. Average bit error (BER) simulations are presented to verify the efficiency of the proposed method.
01 Jan 2014
TL;DR: In this article, the diversity gain of Alamouti MIMO SC-FDE in frequency selective channels was analyzed under linear equalizers such as zero forcing (ZF) and MMSE equalizers.
Abstract: Single-Carrier Frequency Domain Equalizer (SC- FDE) scheme has several advantages than multi-carrier scheme OFDM. SC-FDE avoids all the drawbacks of OFDM. This paper analyzes the diversity gain of multi-input-multi-output (MIMO) SC- FDE in frequency selective channels. This paper fully analyzes the Alamouti signaling scheme under linear equalizers such as Zero- forcing (ZF) and MMSE equalizers. The diversity gain is function of channel memory v, data block length L, data rate R and antenna configuration. Below a threshold rate full diversity is achieved, while at higher rate diversity decreases. Our analysis shows that the diversity of Alamouti MIMO SC-FDE is improved at higher rates i.e twice the diversity of conventional SISO scheme.