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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01 Feb 2014
TL;DR: The paper demonstrates that the effectiveness of proposed algorithm under low signal-to-noise ratios (SNRs), short sensing times, and various channel conditions are demonstrated.
Abstract: Blind Parameter Estimation and classification is a key task in military and commercial applications such as electronic warfare, spectrum monitoring, and spectrum awareness in cognitive radio systems. Cyclostationary signals is one, that exhibits a statistical property to identify whether the signal is treated to be a stochastic or a deterministic time. However there are many criterias to be developed, led to investigate the problem in digital modulation. The problems are overcome by using different algorithms which includes Single Carrier Linearly Digitally modulated (SCLD) signals, Orthogonal Frequency Division Multiplexing (OFDM), Block Transmitted-Single Carrier Linearly Digitally modulated (BT-SCLD) signals. Analytical closed-form expressions are derived for the cyclic autocorrelation function (CAF), cyclic spectrum (CS), complementary CAF (CCAF), and corresponding cycle frequencies (CFs). Furthermore, the conditions for avoiding aliasing in the cycle and spectral frequency domains are obtained. The paper demonstrates that the effectiveness of proposed algorithm under low signal-to-noise ratios (SNRs), short sensing times, and various channel conditions.
1 citations
17 Jun 2007
TL;DR: This paper presents an iterative frequency-domain receiver for joint equalization, residual carrier synchronization and ACI (Adjacent Channel Interference) suppression, and shows that the proposed receiver is able to cope with strong ACI levels, even with only a coarse synchronization between users.
Abstract: This paper considers the uplink of wireless systems using SC-FDE schemes (Single-Carrier with Frequency-Domain Equalization) with OQPSK (Offset Quaternary Phase Shift Keying) modulations. We have an asynchronous scenario where only a coarse synchronization between mobile terminals and the base station is required. We present an iterative frequency-domain receiver for joint equalization, residual carrier synchronization and ACI (Adjacent Channel Interference) suppression. Our performance results show that the proposed receiver is able to cope with strong ACI levels, even with only a coarse synchronization between users.
1 citations
Cites background from "Frequency domain equalization for s..."
...Our performance results show that the proposed receiver is able to cope with strong ACI levels, even with only a coarse synchronization between users.1 I. Introduction Future broadband wireless systems will have very high transmission rates, combined with high power and spectral efficiencies....
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24 Sep 2009
TL;DR: Monte-Carlo simulation results verify that the proposed scheme could achieve order-two cooperative diversity gain and performance gain by 3 dB than the conventional scheme with the same spectral efficiency.
Abstract: A new two-user cooperative transmission scheme with low-complexity frequency-domain equalization (FDE) for single carrier frequency division multiple access (SC-FDMA) systems in localized subcarrier mapping mode is proposed for uplink wireless transmission in this paper. At the destination, each user's information can be obtained with a simpler diversity combing and a lower-complexity FDE than existing schemes. In order to effectively utilize resource, the two users transmit their information using their own allocated transmission subcarriers. At the same time, they exchange information using each partner's allocated transmission subcarriers, and complete one cooperative process in two time slots with amplify-and-forward (AF) cooperative method. The proposed scheme could achieve full cooperative diversity over frequency-selective fading channel without multiple transmit antennas adopted at the users. Monte-Carlo simulation results verify that, with the same spectral efficiency, the proposed scheme could achieve performance gain by 2 dB than the distributed Alamouti-like space-time block codes (STBC) in cluster-based cooperative communication Single-carrier FDE (SC-FDE) systems.
1 citations
Cites background from "Frequency domain equalization for s..."
...Single-carrier frequency-domain equalization (SC-FDE) having a similar structure and performance to orthogonal frequency division multiplexing (OFDM), was shown to be an attractive solution for broadband wireless communications systems [7]....
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01 Jan 2018
TL;DR: A single-carrier scheme with frequency domain equalization (SC-FDE) and a multiple-input multiple-output (MIMO) scheme are proposed and their basic performance in several scenarios with computer simulations are evaluated.
Abstract: We previously developed a high-definition (HD) wireless camera using millimeter waves with the orthogonal frequency division multiplexing (OFDM) scheme. Now, we are developing an 8K wireless camera that can achieve larger transmission capacity with a smaller transmitter. Considering this, we study a single-carrier scheme with frequency domain equalization (SC-FDE) and a multiple-input multiple-output (MIMO) scheme. The SC-FDE could achieve a smaller peak-to-average power ratio, resulting in a smaller power amplifier. In this paper, we propose two structures of 2×2MIMO SC-FDE and evaluate their basic performance in several scenarios with computer simulations.
1 citations
Cites methods from "Frequency domain equalization for s..."
...2 shows the sent data structure of the SISO SC-FDE....
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...Table I contains the transmission parameters of the MIMO SC-FDE for the wireless camera, and the capacity of the MIMO scheme is 1.86 times larger than that of the SISO scheme....
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...Considering this, we study a single-carrier scheme with frequency domain equalization (SC-FDE) and a multiple-input multiple-output (MIMO) scheme....
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...The MIMO SC-FDE will be developed based on the previously studied SISO SC-FDE, which is briefly described below....
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...The SC-FDE could achieve a smaller peak-toaverage power ratio, resulting in a smaller power amplifier....
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27 Jun 2011
TL;DR: This paper shows that by applying a frequency domain spectral shaping filter to SC-FDMA, the PAPR of a localized FDMA (LFDMA) signal can be further reduced at the expense of degraded bandwidth efficiency.
Abstract: The low peak-to-average power ratio (PAPR) in singlecarrier systems has motivated the Long Term Evolution (LTE) Third Generation Partnership Project (3GPP) to adopt single carrier frequency division multiple access (SC-FDMA) as the uplink multiple access scheme. In a single-carrier (SC) system, traditional time domain pulse shaping is used to bandlimit the transmit signal. In this paper we show that by applying a frequency domain spectral shaping filter to SC-FDMA, the PAPR of a localized FDMA (LFDMA) signal can be further reduced at the expense of degraded bandwidth efficiency. Simulation results show that a PAPR reduction of 1.3 dB can be achieved for LFDMA when a raised cosine frequency domain spectral shaping filter with a roll-off factor of 0.22 is applied. Compared to the unfiltered system, the resulting bandwidth efficiency is 78.1%. This PAPR reduction can be used to enhance the power efficiency of the handset, or alternatively to improve uplink throughput and/or operating range.
1 citations
Cites background from "Frequency domain equalization for s..."
...Signals that have a high PAPR, and thus require linear amplification, do not lend themselves easily to power efficient RF amplification [4]....
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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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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