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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TL;DR: Simulation results show that the proposed system can obtain diversity gain without sacrificing spectral efficiency and approaches the single-user bound.
Abstract: This letter proposes an iterative multiuser detection scheme using spectral efficient protocol for relay-assisted single- carrier frequency-domain equalization (SC-FDE). The proposed system achieves spatial diversity over fading channels in a distributed fashion. In the proposed system, two sources with user-specific interleavers access a relay simultaneously, which increases spectral efficiency of time-division multiple-access (TDMA)-based relay protocol. Interference from the other source is removed by an iterative detection method in the frequency domain at the destination. Simulation results show that the proposed system can obtain diversity gain without sacrificing spectral efficiency and approaches the single-user bound.
10 citations
Cites background from "Frequency domain equalization for s..."
...S INGLE-CARRIER frequency-domain equalization (SCFDE) has similar performance and essentially the same overall complexity as orthogonal frequency division multiplexing (OFDM) [1]....
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...Recently, the SC-FDE has drawn a great attention as an alternative to the OFDM, especially in the uplink communications where lower peak-to-average power ratio significantly benefits the mobile terminal in terms of transmit power efficiency....
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...I. INTRODUCTION S INGLE-CARRIER frequency-domain equalization (SC-FDE) has similar performance and essentially the same overall complexity as orthogonal frequency division multiplexing (OFDM) [1]....
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01 Dec 2011
TL;DR: Frequency-domain space-time block coded-joint transmit/ receive diversity (FD-STBC-JTRD) for downlink transmission of single-carrier DAN uses frequency-domain pre-equalization (pre-FDE) instead of receive FDE to keep the mobile terminal's complexity low, and achieves the full-diversity gain.
Abstract: In this paper, we investigate how a distributed antenna network (DAN) offers better throughput performance than a conventional cellular network (CN). In DAN, a group of multiple antennas are distributed in each cell of the CN in order to mitigate the adverse effect of path loss. Moreover, antenna diversity technique can make use of shadowing and multipath fading to improve the transmission performance due to a large spatial diversity gain. In this paper, we consider frequency-domain space-time block coded-joint transmit/ receive diversity (FD-STBC-JTRD) for downlink transmission of single-carrier (SC) DAN. FD-STBC-JTRD uses frequency-domain pre-equalization (pre-FDE) instead of receive FDE to keep the mobile terminal's complexity low, and achieves the full-diversity gain. We show by computer simulation that the transmit power for achieving the required throughput can be significantly reduced compared to the conventional CN.
10 citations
Cites background from "Frequency domain equalization for s..."
...Minimum mean square error based FDE (MMSE-FDE) can take advantage of the channel frequency-selectivity and obtain large frequency diversity gain [2, 3]....
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Proceedings Article•
17 Mar 2009TL;DR: Simulation results show that, the PM based systems performance with multipath fading can outperform their performance with single path fading and are at least 5 dB and 12 dB better than the performance over the single path channel, using PM based OFDM and SC-FDE systems.
Abstract: Phase modulation based systems have the advantages of constant envelope (CE) signals and the ability to improve the diversity of multipath channels. In this paper, we study the performance of single-carrier (SC) and orthogonal frequency-division multiplexing (OFDM) systems using phase modulation (PM). Both systems are implemented with frequency domain equalization (FDE) to obtain high diversity gains over the frequency selective multipath fading channels. FDE performance using both zero forcing (ZF) and minimum mean square error (MMSE) is studied over a wide range of multipath fading channel models. Simulation results show that, the PM based systems performance with multipath fading can outperform their performance with single path fading. The performance over the multipath channels is at least 5 dB and 12 dB better than the performance over the single path channel, using PM based OFDM and SC-FDE systems, respectively. The results also show that, when PM is utilized, SC-FDE systems can outperform OFDM systems by about 5 dB.
10 citations
10 Jun 2012
TL;DR: A performance evaluation of 60 GHz high-speed radio systems under an application scenario related to a medical operation reveals that OFDM systems provide the required throughput for the application scenario in all the measured PDPs.
Abstract: This paper presents a performance evaluation of 60 GHz high-speed radio systems under an application scenario related to a medical operation. The evaluation is based on the following specifications: IEEE 802.15.3c and IEEE 802.11ad, which have been designed to provide data rates of multi-Gbps at physical layer. First, by using measured power delay profiles (PDPs) in hospital environments, both inter-symbol-interference (ISI) and channel capacity are calculated. Then, system simulations are carried out in order to show achievable throughputs. The results reveal that OFDM systems provide the required throughput for the application scenario in all the measured PDPs. On the other hand, the single carrier (SC) systems without any equalization are limited to 85 % of the measured PDPs where the required throughput is achieved. Also, it is shown that the calculated channel capacity for each measured PDP reveals the similar trend with the available throughputs obtained from the system simulations.
10 citations
Cites background from "Frequency domain equalization for s..."
...On the other hand, the OFDM technology is more robust against multipath channels [4]....
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...The reason why both systems have been included is that each system has its own advantages; SC systems enable lowpower consumption transceiver since their peak-to-average ratio (PAPR) are much smaller than that of OFDM signals [4]....
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TL;DR: A joint transmit and receive linear filtering based on minimum mean square error criterion (joint Tx/Rx MMSE filtering) for single-carrier (SC) multiple-input multiple-output (MIMO) transmission is proposed.
Abstract: In this paper, we propose a joint transmit and receive linear filtering based on minimum mean square error criterion (joint Tx/Rx MMSE filtering) for single-carrier (SC) multiple-input multiple-output (MIMO) transmission. Joint Tx/Rx MMSE filtering transforms the MIMO channel to the orthogonal eigenmodes to avoid the inter-antenna interference (IAI) and performs MMSE based transmit power allocation to sufficiently suppress the inter-symbol interference (ISI) resulting from the severe frequency-selectivity of the channel. Rank adaptation and adaptive modulation are jointly introduced to narrow the gap of received signal-tointerference plus noise power ratio (SINR) among eigenmodes. The superiority of the SC-MIMO transmission with joint Tx/Rx MMSE filtering and joint rank adaptation/adaptive modulation is confirmed by computer simulation. key words: single-carrier transmission, MIMO, MMSE filtering, rank adaptation, adaptive modulation
10 citations
Cites methods from "Frequency domain equalization for s..."
...On the other hand, in [10], joint transmit and receive MMSE based frequency-domain equalization (joint Tx/Rx MMSE-FDE) was proposed for SC block transmission....
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...By performing MMSE based transmit power allocation across frequencies, joint Tx/Rx MMSE-FDE sufficiently suppresses the ISI and achieves a better performance than Rx MMSE-FDE [11] which uses the CSI at the receiver only....
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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