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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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01 Jan 2013
TL;DR: A Bit Error Rate Analysis for MIMO-OFDM System is provided and a comparative study with in phase component to show the better noise reduction parameters has also been studied.
Abstract: In this paper Multiple-Input-Multiple-Output (MIMO) System is proposed which uses multiple antennas at the transmitter as well as at the receiver ends of a wireless communication system. MIMO systems are mainly used and applicable because of the increasing efficiency with several antennas. If more than one antenna is used, system uses the wide spatial area with respect to time and frequency domain without affecting the channel bandwidth. For a generic communications links, proposed work focuses on transmitter diversity in lieu of traditional receiver diversity. Using the flat-fading Rayleigh Channel, it illustrates the concept of Orthogonal Space-Time Block Coding, which is employable when multiple transmitter antennas are used. Here it is assumed that the channel undergoes independent fading between the multiple transmit-receive antenna pairs. For a chosen system, it also provides a measure of the performance degradation when the channel is imperfectly estimated at the receiver, compared to the case of perfect channel knowledge at the receiver. In this paper, a Bit Error Rate Analysis for MIMO-OFDM System is provided and a comparative study with in phase component to show the better noise reduction parameters has also been studied. The Receive as well as Transmitter diversity by applying coherent binary phase-shift keying (BPSK) modulation over flat-fading Rayleigh channels have also been focused. For transmit diversity, 1 ∗ 1, 1 ∗ 2, 2 ∗ 1, 2 ∗ 2, 4 ∗ 1a nd 4∗ 2 antenna configurations are implemented and the results shows the close agreement with theoretical aspects. The simulation results show that the proposed system outperforms previously proposed systems in related literature in which these systems had been analyzed without STBC for BER performance.

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

  • ...Moreover, it has some additional benefits like low envelope fluctuations and transmitter simplicity [1,2]....

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DissertationDOI
01 Jan 2014
TL;DR: Simulation results show that by using the proposed technique, it is possible to add more users to any SC- FDMA system without increasing the bandwidth or the modulation order while keeping the same performance in terms of bit error rate (BER) as the conventional SC-FDMA.
Abstract: Single Carrier Frequency Division Multiple Access (SC-FDMA) is a multiple access transmission scheme that has been adopted in the 4th generation 3GPP Long Term Evolution (LTE) of cellular systems. In fact, its relatively low peak-to-average power ratio (PAPR) makes it ideal for the uplink transmission where the transmit power efficiency is of paramount importance. Multiple access among users is made possible by assigning different users to different sets of non-overlapping subcarriers. With the current LTE specifications, if an SC-FDMA system is operating at its full capacity and a new user requests channel access, the system redistributes the subcarriers in such a way that it can accommodate all of the users. Having less subcarriers for transmission, every user has to increase its modulation order (for example from QPSK to 16QAM) in order to keep the same transmission rate. However, increasing the modulation order is not always possible in practice and may introduce considerable complexity to the system. The technique presented in this thesis report describes a new way of adding more users to a SC-FDMA system by assigning the same sets of subcarriers to different users. The main advantage of this technique is that it allows the system to accommodate more users than conventional SC-FDMA and this corresponds to increasing the spectral efficiency without requiring a higher modulation order or using more bandwidth. During this work, special attentions were paid to the cases where two and three source signals are being transmitted on the same set of subcarriers, which leads respectively to doubling and tripling the spectral efficiency. Simulation results show that by using the proposed technique, it is possible to add more users to any SC-FDMA system without increasing the bandwidth or the modulation order while keeping the same performance in terms of bit error rate (BER) as the conventional SC-FDMA. This is realized by slightly increasing the energy per bit to noise power spectral density ratio (Eb/N0) at the transmitters.

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

  • ...Thus, one can expect the two systems to have similar link level performance and spectral efficiency [10]....

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01 Jan 2010
TL;DR: In this article, a single carrier ATSC DTV baseband transmitter, part of the receiver, and channel estimator were modeled since multi-path induced ISI (inter symbol inte
Abstract: In this thesis, a single carrier ATSC DTV baseband transmitter, part of the receiver(including channel estimator and channel equalizer), were modeled Since multi-pathinduced ISI (inter symbol inte
Proceedings ArticleDOI
02 Jun 2013
TL;DR: A low complexity linear FDE is proposed which incorporates knowledge of the channel estimation error variance and derive analytical BER expressions and it is shown that its performance becomes more robust in the presence of strongChannel estimation error components compared with a conventional FDE receiver.
Abstract: Imperfect channel estimation can have a severe impact on the performance of coherent detection systems. In this paper we study the effect of imperfect channel knowledge in the performance of SC-FDE (Single Carrier with Frequency Domain Equalization). We propose a low complexity linear FDE which incorporates knowledge of the channel estimation error variance and derive analytical BER expressions. It is shown that its performance becomes more robust in the presence of strong channel estimation error components compared with a conventional FDE receiver. We also compare the degradation caused by imperfect channel estimation in SC-FDE and in OFDM schemes (Orthogonal Frequency Division Multiplexing) and show that the channel estimation requirements for SC-FDE are higher than for OFDM.

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

  • ...An attractive alternative for this case lies on single carrier block transmissions with frequency domain equalization (SC-FDE) [1][2]....

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Proceedings ArticleDOI
25 Nov 2002
TL;DR: This paper shows the performance improvement of a home LAN using CSMA/CD MAC through simulation and analytic estimation when multi-carrier modulation is applied to a collision resolution technique to utilise a redundancy in the frequency domain and compares it with the one of HomePNA 2.0 MAC in terms of throughput and delay.
Abstract: Non-deterministic MAC (media access control) such as CSMA/CD (carrier sense multiple access/collision detection) is popular due to its simple mechanism in terms of maintenance and extensibility of the LAN. On the other hand, its performance is less predictable as its collision resolution period is not deterministic. Such non-deterministic nature makes it difficult to guarantee the QoS (quality of service) of real-time packets depending on collision resolution algorithms. This paper shows the performance improvement of a home LAN using CSMA/CD MAC through simulation and analytic estimation when multi-carrier modulation is applied to a collision resolution technique to utilise a redundancy in the frequency domain and compares it with the one of HomePNA 2.0 MAC in terms of throughput and delay.
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