Frequency domain equalization for single-carrier broadband wireless systems
TL;DR: This article surveys frequency domain equalization (FDE) applied to single-carrier (SC) modulation solutions and discusses similarities and differences of SC and OFDM systems and coexistence possibilities, and presents examples of SC-FDE performance capabilities.
Abstract: Broadband wireless access systems deployed in residential and business environments are likely to face hostile radio propagation environments, with multipath delay spread extending over tens or hundreds of bit intervals. Orthogonal frequency-division multiplex (OFDM) is a recognized multicarrier solution to combat the effects of such multipath conditions. This article surveys frequency domain equalization (FDE) applied to single-carrier (SC) modulation solutions. SC radio modems with frequency domain equalization have similar performance, efficiency, and low signal processing complexity advantages as OFDM, and in addition are less sensitive than OFDM to RF impairments such as power amplifier nonlinearities. We discuss similarities and differences of SC and OFDM systems and coexistence possibilities, and present examples of SC-FDE performance capabilities.
Citations
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11 May 2006
TL;DR: By computer simulation, it is shown that OFDM/TDM can be used to reduce the clipping level and the required Eb/N0 for the given BER in comparison to OFDM with slight increase in OoB emission.
Abstract: Abstract: Recently, we proposed OFDM combined with time division multiplexing (OFDM/TDM) to alleviate the high peak-to-average power ratio (PAPR) problem of OFDM. To further reduce the PAPR, amplitude clipping can be used. However, the bit error rate (BER) performance degrades and the out-of-band (OoB) power spectrum grows. Therefore, filtering is necessary to suppress the OoB power growth, but the PAPR will regrow. In this paper, by computer simulation, we study PAPR and OoB radiation trade-off of amplitude clipped and filtered OFDM/TDM. We discuss about how, and by how much, clipping affects the OFDM/TDM transmission in terms of PAPR, the power spectrum density (PSD) and the BER degradation. It is shown that OFDM/TDM can be used to reduce the clipping level and the required Eb/N0 for the given BER in comparison to OFDM with slight increase in OoB emission.
2Â citations
Cites methods from "Frequency domain equalization for s..."
...FDE and OFDM/TDM Demodulation One-tap FDE is applied to R(n) as [8]...
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09 Jul 2006
TL;DR: This paper proposes a method for designing the BCCB system matrix coefficients to minimize the mean square error incurred by the LS estimate, by exploiting the eigenvalue characteristic of BCCB matrices.
Abstract: This paper investigates the least-squares (LS) estimation of unknown deterministic parameters from a standard linear model characterized by a class of block-circulant-with-circulant-block (BCCB) matrix. We propose a method for designing the BCCB system matrix coefficients to minimize the mean square error incurred by the LS estimate, under certain equality and inequality constraints. By exploiting the eigenvalue characteristic of BCCB matrices, precise analysis is undertaken to derive a closed-form solution. The considered optimization problem arises in the study of blind channel estimation for single-carrier block transmission with cyclic prefix; the presented analysis reveals several key features associated with the BCCB family, and shows an original investigation of the BCCB matrix structure for facilitating linear optimal parameter estimation.
2Â citations
Cites background from "Frequency domain equalization for s..."
...10) Such a problem arises in the study of blind channel estimation for single-carrier transmission with cyclic prefix [5], [16] and also the related multi-antenna system with space-time block coding [2], [17]....
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02 Mar 2017
TL;DR: It is shown that, for the same spectral efficiency, CPSC-MBM scheme can outperform conventional OFDM and CPSC schemes and a novel message passing based low-complexity algorithm for CPSC -MBM signal detection that scales well and achieves good performance is proposed.
Abstract: A promising modulation scheme called media-based modulation (MBM) is attracting recent research attention. In MBM, radio frequency (RF) mirrors (parasitic elements) are placed near the transmit antenna in order to create different channel fade realizations based on the ON/OFF status of these mirrors, and the resulting complex fade realizations constitute the MBM channel alphabet. The key advantages of MBM are: i) the number of bits conveyed through the choice of the OF/OFF status of the mirrors increases linearly with the number of RF mirrors, and ii) it possesses very good performance attributes due to the additive properties of information over multiple receive antennas. In this paper, we present a study of MBM in ISI channels with a focus on cyclic prefixed single carrier (CPSC) systems. Our new contributions in this paper can be summarized as follows: i) it is shown that, for the same spectral efficiency, CPSC-MBM scheme can outperform conventional OFDM and CPSC schemes, ii) an eigen-value based diversity analysis of the CPSC-MBM scheme is presented; simulation results validate the analytically obtained diversity orders, and iii) a novel message passing based low-complexity algorithm for CPSC-MBM signal detection that scales well and achieves good performance is proposed.
2Â citations
Cites background from "Frequency domain equalization for s..."
...We consider single-carrier (SC) approach [14],[15], where bits are organized into data frames and each data frame is transmitted...
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17 May 2009
TL;DR: This paper shows that the FFT/IFFT operation can be seen as the concatenation of two operations: S/P conversion and spreading, and replaces the orthogonal complex spreading codes of this equivalent OFDMA system with traditional Orthogonal spreading codes that are used in DS-CDMA systems.
Abstract: In this paper, main Single Carrier (SC) and Multicarrier (MC) systems with Frequency Domain Equalization (FDE) are reviewed with the objective to identify key features of the evolution path of air interfaces towards 4G. In particular, this paper shows that the FFT/IFFT operation can be seen as the concatenation of two operations: S/P conversion and spreading. We show that the transmitter of an OFDMA system performs a S/P conversion and a multiplication with specific complex spreading codes. By replacing the orthogonal complex spreading codes of this equivalent OFDMA system, with traditional orthogonal spreading codes that are used in DS-CDMA systems, for instance Walsh-Hadamard codes, we achieve a novel multicode-CDMA system. The comparison of this novel SC transmission scheme with other SC and MC systems shows that the novel SC system has almost the same performance as OFDMA and also similar PAPR. On the other hand, it has a pretty different behavior wrt other SC systems such as IFDMA and DS-CDMA with FDE.
2Â citations
Cites background from "Frequency domain equalization for s..."
...It has been recently shown that cyclic-prefixed single-carrier systems (i.e DS-CDMA, multicode DS-CDMA and also High Speed Downlink Packet Access) with FDE can achieve performance close to the one of a multicarrier-based system with the same receiver complexity [2]- [3]....
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TL;DR: A cooperative single-carrier transmission scheme considering a distributed quasi-orthogonal space-frequency block code (QOSFBC) that provides improved peak-to-average power ratio (PAPR) performance is constructed for uplink communications.
Abstract: In this paper, a cooperative single-carrier transmission scheme considering a distributed quasi-orthogonal space-frequency block code (QOSFBC) that provides improved peak-to-average power ratio (PAPR) performance is constructed for uplink communications. Focused on reducing the size and computational complexity, the source node, i.e., the mobile devices, is equipped with two transmit antennas, while only one antenna is required at the relay node in order to collaboratively generate a distributed QOSFBC signal using four transmit antennas. To achieve full diversity, a phase rotation strategy is proposed at the relay node. In addition, since single-carrier schemes considering SFBCs re-permute the spectral components of the transmitted signal and induce high PAPR value, a modified SFBC coding technique is proposed that allows the high-PAPR problem to be mitigated. Consequently, the designed distributed single-carrier frequency-division multiple access (SC-FDMA) QOSFBC scheme is able to provide full transmit diversity over frequency-selective fading channels, with a lower PAPR value on mobile devices when compared with a conventional SC-FDMA QOSFBC scheme.
2Â citations
Cites background or methods from "Frequency domain equalization for s..."
...For the signal transmission in frequency domain, the singlecarrier frequency-domain equalization (SC-FDE) [9], [10] technique is promising for combating the frequency selective fading channel effect....
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...Compared with conventional OFDMbased schemes, SC-FDE has significantly improved the peakto-average power ratio (PAPR) performance, and is less sensitive to the carrier frequency offset [10]....
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References
More filters
Book•
01 Jan 1986
TL;DR: In this paper, the authors propose a recursive least square adaptive filter (RLF) based on the Kalman filter, which is used as the unifying base for RLS Filters.
Abstract: Background and Overview. 1. Stochastic Processes and Models. 2. Wiener Filters. 3. Linear Prediction. 4. Method of Steepest Descent. 5. Least-Mean-Square Adaptive Filters. 6. Normalized Least-Mean-Square Adaptive Filters. 7. Transform-Domain and Sub-Band Adaptive Filters. 8. Method of Least Squares. 9. Recursive Least-Square Adaptive Filters. 10. Kalman Filters as the Unifying Bases for RLS Filters. 11. Square-Root Adaptive Filters. 12. Order-Recursive Adaptive Filters. 13. Finite-Precision Effects. 14. Tracking of Time-Varying Systems. 15. Adaptive Filters Using Infinite-Duration Impulse Response Structures. 16. Blind Deconvolution. 17. Back-Propagation Learning. Epilogue. Appendix A. Complex Variables. Appendix B. Differentiation with Respect to a Vector. Appendix C. Method of Lagrange Multipliers. Appendix D. Estimation Theory. Appendix E. Eigenanalysis. Appendix F. Rotations and Reflections. Appendix G. Complex Wishart Distribution. Glossary. Abbreviations. Principal Symbols. Bibliography. Index.
16,062Â citations
"Frequency domain equalization for s..." refers methods in this paper
...Adaptation can be done with LMS (least mean square), RLS, or least squares minimization (LS) techniques, analogous to adaptation of time domain equalizers [Hay96], [Cla98]....
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...Overlap-save or overlap-add signal processing techniques could also be used to avoid the extra overhead of the cyclic prefix [Fer85], [Hay96]....
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TL;DR: The analysis and simulation of a technique for combating the effects of multipath propagation and cochannel interference on a narrow-band digital mobile channel using the discrete Fourier transform to orthogonally frequency multiplex many narrow subchannels, each signaling at a very low rate, into one high-rate channel is discussed.
Abstract: This paper discusses the analysis and simulation of a technique for combating the effects of multipath propagation and cochannel interference on a narrow-band digital mobile channel. This system uses the discrete Fourier transform to orthogonally frequency multiplex many narrow subchannels, each signaling at a very low rate, into one high-rate channel. When this technique is used with pilot-based correction, the effects of flat Rayleigh fading can be reduced significantly. An improvement in signal-to-interference ratio of 6 dB can be obtained over the bursty Rayleigh channel. In addition, with each subchannel signaling at a low rate, this technique can provide added protection against delay spread. To enhance the behavior of the technique in a heavily frequency-selective environment, interpolated pilots are used. A frequency offset reference scheme is employed for the pilots to improve protection against cochannel interference.
2,627Â citations
"Frequency domain equalization for s..." refers background in this paper
...OFDM transmits multiple modulated subcarriers in parallel [ 1 ]....
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...Several variations of orthogonal frequency-division multiplexing (OFDM) have been proposed as effective anti-multipath techniques, primarily because of the favorable trade-off they offer between performance in severe multipath and signal processing complexity [ 1 ]....
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TL;DR: In this contribution the transmission of M-PSK and M-QAM modulated orthogonal frequency division multiplexed (OFDM) signals over an additive white Gaussian noise (AWGN) channel is considered and the degradation of the bit error rate is evaluated.
Abstract: In this contribution the transmission of M-PSK and M-QAM modulated orthogonal frequency division multiplexed (OFDM) signals over an additive white Gaussian noise (AWGN) channel is considered. The degradation of the bit error rate (BER), caused by the presence of carrier frequency offset and carrier phase noise is analytically evaluated. It is shown that for a given BER degradation, the values of the frequency offset and the linewidth of the carrier generator that are allowed for OFDM are orders of magnitude smaller than for single carrier systems carrying the same bit rate. >
1,816Â citations
TL;DR: This correspondence describes the construction of complex codes of the form exp i \alpha_k whose discrete circular autocorrelations are zero for all nonzero lags.
Abstract: This correspondence describes the construction of complex codes of the form exp i \alpha_k whose discrete circular autocorrelations are zero for all nonzero lags. There is no restriction on code lengths.
1,624Â citations