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Journal ArticleDOI

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.

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Citations
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Proceedings ArticleDOI
16 May 2005
TL;DR: The results demonstrate performance advantage of the SC-FDE scheme, especially when implementation issues such as low complexity and low power consumption for UWB are taken into consideration.
Abstract: This paper investigates the performance of cyclic prefixed single carrier with frequency domain equalization (SC-FDE) transmission over the ultra-wideband (UWB) propagation environment. The performance of SC-FDE over IEEE 802.153a UWB channel models is analyzed, simulated and compared with that of impulse based single carrier UWB (SC-UWB) and multicarrier UWB (MC-UWB) employing orthogonal frequency-division-multiplexing (OFDM). The impact of channel coding with different code rates on the performance of OFDM and SC-FDE in UWB is also studied. Our results demonstrate conclusive performance advantage of the SC-FDE scheme, especially when implementation issues such as low complexity and low power consumption for UWB are taken into account.

19 citations


Cites background from "Frequency domain equalization for s..."

  • ...When compared with OFDM-UWB, the overall system complexity is similar; however, a lower PAPR value of the transmitted signal is a crucial advantage of SC-FDE over OFDM [6]....

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  • ...Single carrier block transmission with frequency domain equalization (SC-FDE), where data is transmitted block-wisely in the time domain while equalization is carried out in the frequency domain, has been proved to have similar complexity as OFDM, yet provides overall advantages in performance and implementation [6], [7], [8]....

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  • ...The frequency domain equalization performs FFT/IFFT, at complexity of O(N log2 N) [6]....

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Proceedings ArticleDOI
15 Jun 2003
TL;DR: Techniques are presented and analyzed that aim at omitting the guard periods in high data rate transmissions over time dispersive channels without increasing the computational complexity significantly.
Abstract: To meet the requirement of efficient cancellation of intersymbol interference (ISI) in high data rate transmissions over time dispersive channels block based transmissions are often adopted. This is the case in orthogonal frequency domain multiplexing (OFDM), cyclic prefix based single carrier (CP-SC) and block transmissions with null guard periods (ZP-SC). Guard periods are inserted between the data blocks that lower the spectral efficiency significantly. In this paper techniques are presented and analyzed that aim at omitting the guard periods in the aforementioned systems without increasing the computational complexity significantly. One is the application of overlapping methods, another the reasonable selection of the block size, a third the usage of guard periods shorter than the initial ones. The techniques can be combined arbitrarily. They are applied in transmissions over a mobile vector channel and assessed in terms of bit error rate (BER), spectral efficiency and computational complexity.

19 citations


Cites background from "Frequency domain equalization for s..."

  • ...They are all applied or proposed in high data rate wireless communications....

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Journal ArticleDOI
TL;DR: The soft estimates of the transmitted symbols provided by the BI-GDFE are utilized to estimate the channel via an expectation maximization (EM)-based algorithm and a joint channel estimation and data detection receiver is developed.
Abstract: In this paper, we are interested in the problem of joint channel estimation and data detection for multi-input multi-output (MIMO) interleaved frequency division multiple access (IFDMA) systems. Although IFDMA is free from the multiple access interference (MAI), it suffers from intersymbol interference (ISI). MIMO-IFDMA system suffers from both ISI and multi-stream interference (MSI). The block iterative generalized decision feedback equalizer (BI-GDFE) is an iterative and effective interference cancellation scheme which could provide near maximum likelihood (ML) performance with very low complexity. However, BI-GDFE needs the channel state information (CSI). In this paper, we utilize the soft estimates of the transmitted symbols provided by the BI-GDFE to estimate the channel via an expectation maximization (EM)-based algorithm. By doing so, a joint channel estimation and data detection receiver is developed. To evaluate the performance of the proposed channel estimation algorithm, we derive the Cramer-Rao lower bound (CRLB). Computer simulations show that the bit error rate (BER) performance of the proposed joint channel estimation and signal detection receiver can reach the performance of the BI-GDFE with perfect CSI.

19 citations


Cites methods from "Frequency domain equalization for s..."

  • ...When the number of repetitions in IFDMA systems equals to 1, MIMO-IFDMA model reduces to a single-user MIMO single carrier cyclic-prefix system [11, 12] (MIMO-SCCP)....

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Proceedings ArticleDOI
02 Jul 2012
TL;DR: In this paper, advanced block-transmission schemes for dispersive optical channels with intensity modulation and direct detection are discussed and compared in the framework of orthogonal frequency division multiplex or its real valued base-band derivate discrete multitone transmission (DMT).
Abstract: In this paper, advanced block-transmission schemes for dispersive optical channels with intensity modulation and direct detection are discussed and compared In the framework of orthogonal frequency division multiplex or its real valued base-band derivate discrete multitone transmission (DMT) we analyze DC-biased DMT, pulse-amplitude modulated DMT as well as asymmetrically clipped DMT The results are compared to those of base-band pulse-amplitude modulation with frequency domain equalization The dispersive optical channel is modeled as a Gaussian type low-pass filter Closed-form expressions to estimate the required optical power are presented Under the constraint of using power loading and no bit loading, we show that frequency domain equalization outperforms DMT

19 citations

Proceedings ArticleDOI
23 Sep 2011
TL;DR: In this paper, recent advance in gigabit DAN is presented, with particular attention paid to frequency-domain multi-input/multi-output (MIMO) diversity, relay, beamforming, and multiplexing jointly used with frequency- domain equalization (FDE) to significantly improve the signal transmission quality over a service area.
Abstract: For gigabit wireless data services, there are three important technical issues to be addressed: limited bandwidth, severe frequency-selective fading, and limited transmit power. A distributed antenna network (DAN) is a promising solution to the above three technical issues. In this paper, recent advance in gigabit DAN is presented. In DAN, each mobile user is served by using multiple distributed antennas close to it. Particular attention is paid to frequency-domain multi-input/multi-output (MIMO) diversity, relay, beamforming, and multiplexing jointly used with frequency-domain equalization (FDE) to significantly improve the signal transmission quality over a service area.

19 citations


Cites background from "Frequency domain equalization for s..."

  • ...Frequency-domain signal processing, e.g., frequency-domain equalization (FDE) [2], [3], may play an important role in achieving a good signal transmission performance in such a severe frequency-selective channel....

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  • ..., frequency-domain equalization (FDE) [2], [3], may play an important role in achieving a good signal transmission performance in such a severe frequency-selective channel....

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  • ...A frequency-domain spacetime block coded joint transmit/receive diversity (FD-STBC- JTRD) combined with transmit FDE allows the use of an arbitrary number Ndan of distributed transmit antennas while the number of MT receive antennas is limited to Nmt≤6 [5]....

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  • ...After performing the transmit FDE weight multiplication and inserting a cyclic prefix (CP) into the guard interval (GI) of each Nc-symbol block, Ndan streams of Q blocks each are transmitted from Ndan distributed antennas....

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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.

16,062 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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Journal ArticleDOI
Jr. L.J. Cimini1
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.

2,627 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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Book
Simon Haykin1
01 Mar 1991

2,447 citations

Journal ArticleDOI
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. >

1,816 citations

Journal ArticleDOI
D. Chu1
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.

1,624 citations