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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16 Sep 2022
TL;DR: In this article , the authors compared OFDM, single carrier frequency division multiple access (SCFDMA), filter bank multi-carrier (FBMC), and generalized frequency-division multiplexing (GFDM) waveforms.
Abstract: Orthogonal frequency division multiplexing (OFDM) system is not suitable for fifth-generation (5G) applications as it has strict synchronization requirement, high out of band (OBB) leakage due to use of rectangular pulse shaping, less spectrum efficiency due to use of cyclic prefix (CP), high bit error rate (BER), etc. Pulse shape waveforms have been proposed to be a suitable candidate for 5G. This paper investigates OFDM, single carrier frequency division multiple access (SCFDMA), filter bank multi-carrier (FBMC), and generalized frequency division multiplexing (GFDM) waveforms. It has been observed that pulse-based techniques have better performance in terms of BER, PAPR, and spectrum efficiency. The comparative study reveals that OFDM has the highest PAPR while the FBMC system has the lowest value among the four systems investigated.
Journal Article•
TL;DR: Simulation result proves that the proposed algorithm for parameters estimation of SCFDE signals improves the estimation accuracy, and has a better estimation performance even in the low noise signal ratio.
Abstract: () )) )This paper deeply analyzes the cyclic autocorrelation property of Single CarrierFrequency Domain Equa lization(SCFDE) signals and discusses the relationship between the cyclic autocorrelation function and the length of the useful signals and cyclic prefix. With no prior information, an algorithm for parameters estimation of SCFDE signals is proposed. According to the property that the cross section is symmetrical about zero and the relationship between the length of cyclic prefix and the spectral line, this paper restricts the search of spectral peak to a specified region and estimates the length and the symbol number of the cyclic prefix. Simulation result proves that the algorithm improves the estimation accuracy, and has a better estimation performance even in the low noise signal ratio.
04 Sep 2006
TL;DR: An innovative frequency domain detection strategy is tested in two different indoor short-range communication scenarios where several mobile terminals transmit low or high data-rate flows to a base station and shows that the proposed approach is well suited for the considered scenarios.
Abstract: Low and high data-rate applications can be foreseen for future ultra-wideband systems which are based on impulse radio and proper detection schemes have to be designed for the most general scenarios. In this paper, an innovative frequency domain detection strategy is tested in two different indoor short-range communication scenarios where several mobile terminals transmit low or high data-rate flows to a base station. Both Zero Forcing (ZF) and Minimum Mean Square Error (MMSE) criteria have been investigated and compared with the classical RAKE. The results show that the proposed approach is well suited for the considered scenarios.
Cites background or methods from "Frequency domain equalization for s..."
...When using FDE, each block of 1024 samples is extended by means of a CP of 128 samples, so that the channel causes no interference between adjacent blocks....
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...In order to perform FDE [11], each block is extended by means of a cyclic prefix (CP) of length K (see Fig....
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...Frequency Domain Equalization (FDE) [11], proposed and studied for a single-carrier single-user environment, can be applied to multiuser short-range IR communications, affording a good complexity/performance trade off....
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TL;DR: IEEE802.11 やIMT-2000 などのシステムの特性を劣化する．この対策として1950 年代からRAKE 受信方式の研究が行われ，実用化されてきた ．RAKE £20,000
Abstract: 周波数選択性フェージングは移動通信システムの特性を劣化する．この対策として1950 年代からRAKE 受信方式の研究が行われ，実用化されてきた．RAKE 受信方式は広帯域信号を用いることによってマルチパスを分解し，パスダイバーシチにより特性を改善する．RAKE 受信方式はFSK，スペクトル拡散通信などのシステムへの適用が検討され，IEEE802.11 やIMT-2000 などのシステムにおいて実用化されてきた．また最近では，Ultra Wideband システムやマルチキャリヤ変調との組合せも検討されている．本稿ではRAKE 受信方式の原理及びその発展に関して概観する．
24 Oct 2008
TL;DR: Two interference cancellation techniques are proposed in this paper that utilizes the users' mobility condition to determine the detection ordering sequence and results show that the proposed techniques perform well in the presence of high number of users with high mobility.
Abstract: A CDMA scheme employing block processing (BS-CDMA) had been proposed earlier as an effective multiple access scheme that is robust against multiuser interference (MUI) during uplink transmission where conventional CDMA schemes fail due to orthogonality destruction. However, residual MUI arises in BS-CDMA and its degradation impact becomes severe when high mobility users are present. Two interference cancellation techniques are proposed in this paper that utilizes the users' mobility condition to determine the detection ordering sequence. Based on extensive simulation studies, results show that the proposed techniques perform well in the presence of high number of users with high mobility.
Cites background from "Frequency domain equalization for s..."
...In addition, equalization in SC-FDE reduces the dominant degradation impact caused by those subcarriers experiencing deep fades [1]....
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...SC-FDE architecture retains most of the advantages offered by OFDM, while allowing the transmitter complexity to be simple and highly similar to those uplink devices used in the existing generation of mobile communication systems....
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...Direct adoption of CDMA into MC and SC-FDE system was proposed in [2] and [3] referred as MC-CDMA and CPCDMA systems respectively....
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...Over the recent years, the search for alternative to OFDM (especially one that is suitable for uplink deployment) focused on the use of frequency-domain processing for SC system, commonly referred to as SC-FDE [1]....
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...Over the recent years, the search for alternative to OFDM (especially one that is suitable for uplink deployment) focused on the use of frequency-domain processing for SC system, commonly referred to as SC-FDE [1]....
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References
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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