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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10 Apr 2007
TL;DR: The proposed dynamic bandwidth/channel access technique uses single carrier modulation suitable for small output backoff operation in HPA, keeping flexibility and scalability as OFDMA has.
Abstract: [] This paper proposes dynamic bandwidth/channel access technique using FFT based block signal transmission for future broadband mobile satellite communication systems, which is to supplement next generation terrestrial mobile networks. One of the key issues for next generation mobile satellite communication systems is flexible and scalable access technique in terms of data rate and traffic type, to accommodate various satellite users. OFDMA is a technique to meet the above-mentioned requirements, however it needs large output backoff at HPA. To solve this problem, this paper proposes a new bandwidth/channel access technique using FFT based block signal transmission. The proposed technique uses single carrier modulation suitable for small output backoff operation in HPA, keeping flexibility and scalability as OFDMA has. This paper describes basic principle of the proposed dynamic bandwidth/channel access technique and preliminary performance evaluation results by computer simulation.
1 citations
21 Apr 2012
TL;DR: The performance simulated of the space-time block coding orthogonal frequency division multiplexing (STBC-OFDM) system under different channel conditions is found to be much better than the OFDM system without using Space-time coded.
Abstract: This paper analyzes the performance simulated of the space-time block coding orthogonal frequency division multiplexing (STBC-OFDM) system under different channel conditions after studying the STBC-OFDM system. From that it can be found that the BER performance of STBC-OFDM system is much better than the OFDM system without using Space-time coded.
1 citations
Cites methods from "Frequency domain equalization for s..."
...So the design of STC needs to use the technologies such as channel equalization and system design becomes very complicated....
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01 Nov 2013
TL;DR: Two symbol timing synchronization algorithms based on a novel structure of training symbol that can take advantage of the correlations of the four parts of the training symbol to efficiently improve the accuracy of timing synchronization and the anti-multipath capability are proposed.
Abstract: Symbol timing synchronization is a key technology for SC-FDE (Single Carrier Frequency Domain Equalization) systems. The traditional Schmidl & Cox's and Minn's algorithms have some shortcoming on the existence of timing metric plateau and redundant peaks. To overcome these shortcomings, two symbol timing synchronization algorithms based on a novel structure of training symbol are proposed for SC-FDE systems in this paper. The proposed methods can take advantage of the correlations of the four parts of the training symbol to efficiently improve the accuracy of timing synchronization and the anti-multipath capability. The simulation results confirm that the performances of the proposed algorithms are superior to Minn's algorithm in AWGN channel and 3GPP Vehicular A channel.
1 citations
Cites background from "Frequency domain equalization for s..."
...On the other hand, SC (Single Carrier) transmission together with low-complexity FDE (Frequency Domain Equalization) can also combat ISI in frequency selective channels [1-3]....
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19 Apr 2009
TL;DR: This paper shows that full diversity can be restored by the introduction of a convolutive linear MIMO precoding scheme that was shown earlier to allow to attain the optimal DMT for ML or DFE detection (in the frequency-flat case).
Abstract: Since the introduction of the Diversity-Multiplexing Tradeoff (DMT) by Zheng and Tse for ML reception in frequency-flat MIMO channels, some results have been obtained also for the DMT of frequency-selective MIMO channels and for the DMT of suboptimal receivers such as linear (LEs) and decision-feedback equalizers (DFEs) for frequency-selective SIMO channels or frequency-flat MIMO channels. We have recently extended these results to the case of linear receivers for frequency-selective MIMO channels. However, the diversity properties of linear receivers turn out to be fairly catastrophic. In this paper we show that full diversity can be restored by the introduction of a convolutive linear MIMO precoding scheme that we showed earlier to allow to attain the optimal DMT for ML or DFE detection (in the frequency-flat case). The precoder needs to be used with a moderate amount of redundancy in the form of zero-padding, and with a MMSE design for the linear equalizer. A MMSE-ZF design also benefits substantially from the precoding. The proposed scheme is a significant extension of an earlier SISO result by Tepelenlioglu to the MIMO case.
1 citations
Additional excerpts
...The use of the DFE appears in [13] (FIR) and [14],[15] (SCCP) where in the last two references diversity behavior is investigated through simulations....
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08 Sep 2014
TL;DR: The goal of this paper is to compare the performance of the proposed DCT-OFDMA-PM system with DCT, which is based on signal transformation using phase modulation (PM) and outperforms in terms of BER and PAPR.
Abstract: Orthogonal Frequency Division Multiplexing (OFDM) is a popular and widely accepted modulation technique in the area of wireless communication. Multi-user version of the OFDM system is called Orthogonal Frequency Division Multiple Access (OFDMA). Although OFDM and OFDMA have many benefits contributing to its popularity, a well-known drawback of multicarrier transmission is its inherited large peak-to-average power ratio (PAPR). The proposed system uses an alternative method to solve the PAPR problem in OFDMA, which is based on signal transformation using phase modulation (PM). The discrete Fourier transform in traditional DFT-OFDMA systems are replaced by a discrete cosine transform (DCT), the resulting DCT-OFDMA system is then used to develop a new transceiver system called DCT-OFDMA-PM. The PM input signal to be modulated must be real which can be produced using DCT-OFDMA with pulse amplitude modulation (M-PAM). Phase modulation based systems have the advantage of constant envelope (CE) signals and the ability to improve the diversity of multipath environment. The goal of this paper is to compare the performance of the proposed DCT-OFDMA-PM system with DCT-OFDMA as well as the traditional DFT-OFDMA system. The simulation result shows that proposed system outperforms in terms of BER and PAPR.
1 citations
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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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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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
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