Frequency domain equalization for single-carrier broadband wireless systems

doi:10.1109/35.995852

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Frequency domain equalization for single-carrier broadband wireless systems

Journal Article•DOI•

Frequency domain equalization for single-carrier broadband wireless systems

David Falconer¹, S.L. Ariyavisitakul, A. Benyamin-Seeyar², B. Eidson³•Institutions (3)

Carleton University¹, Harris Corporation², Conexant³

01 Apr 2002-IEEE Communications Magazine (IEEE)-Vol. 40, Iss: 4, pp 58-66

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.

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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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Proceedings Article•

Amplify-and-Forward Relaying Based Multi-Relay Wireless Network Coding

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Kazunori Hayashi¹, Ryo Takami, Megumi Kaneko¹, Naoki Fukaya, Hideaki Sakai¹ - Show less +1 more•Institutions (1)

Kyoto University¹

04 Oct 2009

TL;DR: This paper proposes a distributed relaying protocol for the multi-relay AFNC, which can cope with the data reflection by using locally available information and introduces the technique of frequency domain equalization (FDE) for the transmission and the detection of signals.

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Abstract: This paper extends the amplify-and-forward based wireless network coding (AFNC) for single-relay network to multi-relay network with a chain topology. Direct application of the relaying protocol utilized in the conventional single-relay AFNC to the multi-relay scenario causes two major problems: the phenomenon of back stream of data, which we call data reflection, and inter-hop interference. We propose a distributed relaying protocol for the multi-relay AFNC, which can cope with the data reflection by using locally available information. Moreover, we introduce the technique of frequency domain equalization (FDE) for the transmission and the detection of signals in order to utilize the interference as informative signal. Computer simulation results show that, with the proposed method, the multi-relay AFNC can be realized and the interference is successfully utilized to improve the throughput performance.

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

...ing, Multi-Relay, FDE I. INTRODUCTION Network Coding (NC) [1] is a packet level coding scheme performed by relay nodes in the network and has been gaining much attention both in wired and wireless communication research communities....
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...Moreover, the inter-hop interference is also one of the multirelay network specific problems, therefore, we introduce the technique of frequency domain equalization (FDE) [7], [8] for the interference problem....
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...For comparison purpose, the throughput performance of the proposed AFNC without the FDE technique is also shown in the same figure for both the case with and without the interference....
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...Computer simulations show that the proposed relaying algorithm enable us to realize multirelay AFNC, and that the proposed AFNC with the FDE technique can achieve better throughput performance than the conventional method without interference for a wide range of signal-to-noise power ratio (SNR) in spite of the requirement of one redundant signal block for the cyclic prefix....
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...From the figure, we can see that the proposed methods can improve throughput performance quite a lot compared with the method without the FDE technique, although the throughput is saturated at M/(M + 1) because of the requirement of one redundant signal block for the cyclic prefix....
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Journal Article•

Single Carrier Transmissions with Joint Antenna Receive Diversity and QRM-MLD

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Yamamoto Tetsuya, Takeda Kazuki, Adachi Fumiyuki

25 Feb 2009-Technical report of IEICE. RCS

TL;DR: MIMO, QR, V-BLAST, QRM-MLD,アンテナダイバーシチ受信信号表現と同様に表わされることから, MIMO 多重における信号検出法が適用できたことを指

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Abstract: あらましマルチ送受信アンテナ(MIMO)空間多重では,受信信号をベクトルとし,チャネルを行列として信号検出する方法がよく知られており,さまざまな信号検出法が提案されている.筆者らはこれまで,シングルキャリア (SC)伝送の周波数領域受信信号が MIMO 多重の受信信号表現と同様に表わされることから,MIMO 多重における信号検出法が適用できることを指摘してきた.本論文では,QR 分解と M アルゴリズムを用いる演算量削減型最尤検出法(QRM-MLD)とアンテナ受信ダイバーシチとを SC 伝送に適用している.そして,このときの誤り率(BER)特性を計算機シミュレーションにより求め, QRM-MLD と受信ダイバーシチと併用することで M アルゴリズムの各ステージにおける生き残りシンボルレプリカ候補数を削減しつつ優れた BER 特性が得られることを示す. キーワードシングルキャリア,V-BLAST 検出,QRM-MLD,アンテナダイバーシチ受信

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Additional excerpts

...まとめ本論文では， SC 伝送に受信ダイバーシチと QRM-MLD を適用した時の BER 特性を計算機シミュレーションにより求め，受信ダイバーシチを用いることで QRM-MLD の M アルゴリズムの各ステージにおける生き残りシンボルレプリカ候補数を削減しつつ優れた BER 特性が得られることを示した．また，受信ダイバーシチと V-BLAST 検出を用いる SC 伝送の BER 特性を求め，QRM-MLD と比較した．受信ダイバーシチと QRM-MLD を併用すれば生き残りシンボルレプリカ候補数 M=4 でフル MLD とほぼ同等の BER 特性が得られる．また，受信ダイバーシチを用いる場合， QRM-MLD は演算量を硬判定および軟判定 V-BLAST と比べて大幅に削減しつつより優れた BER 特性を得ることができる． 1.0E-01 1.0E-02 1.0E-03 1.0E-04 1.0E-05 0 5 10 15 20 QPSK Nc=64 Ng=16 Full MLD Average received Eb/N0 (dB) A ve ra ge B ER Conventional MMSE-FDE QRM-MLD 1.0E-00 25 M=1 M=4 M=16 M=64 M=256 Nr=1 Nr=2 Nr=4 (a) QPSK 1.0E-01 1.0E-02 1.0E-03 1.0E-04 1.0E-05 0 5 10 15 20 16QAM Nc=64 Ng=16 Full MLD Average received Eb/N0 (dB) A ve ra ge B ER Conventional MMSE-FDE QRM-MLD 1.0E-00 25 M=1 M=4 M=16 M=64 M=256Nr=1 Nr=2 Nr=4 (b) 16QAM 図 3 QRM-MLD と受信ダイバーシチを用いる SC 伝送の BER 特性 1.0E-01 1.0E-02 1.0E-03 1.0E-04 1.0E-05 0 5 10 15 20 QPSK Nc=64 Ng=16 Full MLD Average received Eb/N0 (dB) A ve ra ge B ER Conventional MMSE-FDE 1.0E-00 25 QRM-MLD M=256(Nr=1), M=4(Nr=2, 4) Nr=1 Nr=2 Nr=4 Hard decision iterative V-BLAST (i=1) (a) QPSK 1.0E-01 1.0E-02 1.0E-03 1.0E-04 1.0E-05 0 5 10 15 20 16QAM Nc=64 Ng=16 Full MLD Average received Eb/N0 (dB) A ve ra ge B ER Conventional MMSE-FDE 1.0E-00 25 QRM-MLD M=256(Nr=1), M=4(Nr=2, 4) Nr=1 Nr=2 Nr=4 Hard decision iterative V-BLAST (i=1) (b) 16QAM 図 4 QRM-MLD と硬判定繰り返し V-BLAST の比較文献 [1] W. C., Jakes Jr., Ed,. Microwave mobile communications , Wiley, New York, 1974....
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...最近では,最小平均二乗誤差 (MMSE)規範に基づく周波数領域等化を用いれば,周波数ダイバーシチ効果が得られるので SC 伝送のビット誤り率 (BER)特性を大幅に改善できることが示されてきた [3],[4] ....
[...]
...QRM-MLD と V-BLAST 検出との比較図 4 に QRM-MLD と硬判定繰り返し V-BALST を適用した時の SC 伝送の BER 特性を示す．ただし， QRM-MLD における M の値は，Nr=1 のときは 256 とし， Nr=2, 4 のときは 4 としている．硬判定繰り返し V-BLAST では，繰り返しを 2 回以上行っても特性改善が飽和するため，繰り返し回数は 1 回とした．硬判定繰り返し V-BLAST では，検出済みのシンボルによる残留干渉を考慮せずに重みを生成するため残留 ISI を十分に抑圧できない．したがって，Nr=1 の時には，繰り返しを適用しても BER 特性をあまり改善できないことがわかる．受信ダイバーシチを適用することで残留 ISI を抑圧できるため，その特性はフル MLD の BER 特性に近づく．Nr=4 の場合には，繰り返し 1 回で QRM-MLD の M=4 と同等の BER 特性が得られる．したがって，Nr=4 の場合では，軟判定レプリカを用いる必要はなく硬判定レプリカで十分であることがわかる．図 5 に QRM-MLD と軟判定繰り返し V-BALST を適用した時の SC 伝送の BER 特性を示す．ただし， QRM-MLD における M の値は，Nr=1 のときは 256 とし， Nr=2, 4 のときは 4 としている．軟判定繰り返し V-BLAST における繰り返し回数は，十分な改善効果が得られる 1 回とした．軟判定繰り返し V-BLAST では，軟判定レプリカを用いることで誤り伝播の影響を低減でき，さらに残留干渉による影響を考慮して重みベクトルを生成しているため，硬判定繰り返し V-BLAST に比べて優れた特性が得られることがわかる．Nr=2 の場合でも，繰り返し 1 回で QRM-MLD の M=4 と同等の BER 特性が得られる． 5.3....
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...図 3 に QRM-MLD とアンテナ受信ダイバーシチを用いるときの SC 伝送の BER 特性を示す．受信アンテナ数をパラメータとしてプロットした．ここで，横軸 Eb/N0(= (Es/N0)(Nc+Ng)/X)は 1 ビットあたりの平均信号エネルギー対雑音電力スペクトル密度である．また，比較のため従来の MMSE-FDE を用いた場合の平均 BER 特性，およびフル MLD を用いる時の BER 特性も示す．Nr=1 の場合，各ステージにおける生き残りシンボルレプリカ候補数 M の値を 64，256 と大きくしないとフル MLD の BER に近い特性が達成できないことがわかる．これは，M の値が小さい場合には初期のステージで，誤って正しいシンボルレプリカ候補を削除してしまう確率が増加するためである．一方，受信ダイバーシチを用いれば， M=1 の場合でも従来の MMSE-FDE より優れた BER 特性が得られ，平均 BER=10−4 を達成する所要 Eb/N0 は，M=4 でフル MLD とほぼ同等となることがわかる．これは，受信ダイバーシチによって QR 分解の後の上三角行列 R の値が大きくなるため，初期のステージで誤って正しいシンボルレプリカ候補を削除してしまう確率が減少するためである． 5.2....
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...まえがき次世代の移動通信では，高速かつ高品質なデータ伝送の実現が望まれている．移動無線チャネルは，遅延時間の異なる様々な伝搬路から構成される周波数選択性フェージングチャネルであるため，シングルキャリア (SC)伝送では，厳しい符号間干渉 (ISI)が発生し伝送特性が大幅に劣化してしまう [1],[2]．最近では，最小平均二乗誤差 (MMSE)規範に基づく周波数領域等化を用いれば，周波数ダイバーシチ効果が得られるので SC 伝送のビット誤り率 (BER)特性を大幅に改善できることが示されてきた [3],[4] ．しかしながら，従来の MMSE-FDE を用いる SC 伝送では，残留 ISI による伝送特性の劣化が生じてしまう [5]．筆者らは以前，SC 伝送の周波数領域受信信号がマルチ送受信アンテナ (MIMO)の受信信号表現と同様に表わされることから，SC 伝送に MIMO 多重における信号検出法が適用できることを指摘した [6]．そして， MMSE 検出 [2]および Vertical-Bell Laboratories layered space-time architecture (V-BLAST)検出 [7]を SC 伝送に適用した時の BER 特性を明らかにし，V-BLAST を適用した SC 伝送では従来の MMSE-FDE を用いた SC 伝送よりも優れた BER 特性が得られることを示した．しかし，高多値変調では BER の理論的下界からの劣化がまだ残ってしまう．一方，MIMO 多重において最も優れた伝送特性が得られる信号検出法は最尤検出 (MLD) 法 [2, 8]である．しかし，MLD 法を SC 伝送に適用した場合，X を変調レベル，Nc を判定に用いるブロックサイズとして，送信シンボル系列の候補数は XNc となり，信号検出のための演算処理量が膨大になってしまう．文献 [9]では，DFT 拡散 OFDM(SC-FDMA)に QR 分解と M アルゴリズムを用いる演算量削減型 MLD 法 (QRM-MLD)[10]を適用し信号検出を行う方法が提案されており，従来の MMSE に比べて非常に優れた BER 特性が得られることが示されている．QRM-MLD を適用した SC 伝送では，M アルゴリズムの各ステージにおける生き残りシンボルレプリカ候補数を大きくすることで高多値変調においても BER の理論的下界に近い特性が得られる．しかし，生き残りシンボルレプリカ候補数の増加は演算量の増加をともなう．受信ダイバーシチを用いることで，BER の理論的下界に近い特性が得られる生き残りシンボルレプリカ候補数の削減が期待できる．本論文では， SC 伝送に受信ダイバーシチと QRM-MLD を適用した時の BER 特性を計算機シミュレーションにより求め，受信ダイバーシチを用いることで QRM-MLD の M アルゴリズムの各ステージにおける生き残りシンボルレプリカ候補数を削減しつつ優れた BER 特性が得られることを示す．また，先に示した V-BLAST 検出についても受信ダイバーシチを導入し， QRM-MLD と比較している．本論文の構成は以下のようになっている．第 2 章では SC 受信信号の行列表現について述べる．第 3 章ではアンテナダイバーシチ受信を用いる QRM-MLD について述べる．第 4 章では，繰り返し V-BLAST 検出について述べる．第 5 章では，平均 BER 特性を計算機シミュレーションによって求め，最後に第 6 章でまとめる． Data Data modulation +GI d −GI FFT Detection y0 Y0 −GI FFT yNr−1 YNr−1 ... #0 #Nr−1 図 1 受信ダイバーシチを用いるシングルキャリア伝送系 HTx Rx... #0 #1 #Nc−1 ... #0 #1 #NrNc−1 図 2 受信ダイバーシチを用いる SC 伝送と等価である (NrNc×Nc)MIMO チャネル 2....
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Proceedings Article•DOI•

Iterative receiver for single carrier cyclic prefix assisted block transmission systems

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Baojin Li¹, Zhifeng Ruan¹, Yongyu Chang¹, Dacheng Yang¹•Institutions (1)

Beijing University of Posts and Telecommunications¹

12 May 2008

TL;DR: An iterative receiver algorithm is derived for single carrier cyclic prefix (CP) assisted block transmission systems based on iterative frequency domain detection and decoding based on soft inter-symbol interference cancellation and minimum mean-square-error equalization.

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Abstract: An iterative receiver algorithm is derived for single carrier cyclic prefix (CP) assisted block transmission systems. The proposed algorithm is based on iterative frequency domain detection and decoding. At each iteration, soft inter-symbol interference cancellation (ISIC) and minimum mean-square-error (MMSE) equalization both in the frequency domain are used symbol by symbol to minimize the performance degradation caused by frequency-selective channels. We also consider an approximate implementation of the proposed algorithm suffering from little performance loss in exchange for complexity reduction. The bit-error rate (BER) as a function of the signal-to-noise ratio (SNR) is used as a performance measure. In addition, the convergence characteristic of the iterative loop is studied with the extrinsic information transfer (EXIT) chart.

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Dissertation•

High performance faster-than-nyquist signaling

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Bruno Miguel Domingues da Cunha

01 Sep 2014

TL;DR: This thesis considers the use of FTN signaling for the uplink of broadband wireless systems employing SC-FDE based on the Iterative Block with Decision Feedback Equalization (IB-DFE) receiver with a simple scheduled access Hybrid Automatic Repeat reQuest (H-ARQ) specially designed taking into account the characteristics ofFTN signals.

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Abstract: In a wireless broadband context, multi-path dispersive channels can severely affect data communication of Mobile Terminals (MTs) uplink. Single Carrier with Frequency-Domain Equalization (SC-FDE) has been proposed to deal with highly dispersive channels for the uplink of broadband wireless systems. However, current systems rely on older assumptions of the Nyquist theorem and assume that a system needs a minimum bandwidth 2W per MT. Faster-Than-Nyquist (FTN) assumes that it is possible to employ a bandwidth as low as 0.802 of the original Nyquist bandwidth with minimum loss despite this, the current literature has only proposed complex receivers for a simple characterization of the wireless channel. Furthermore, the uplink of SC-FDE can be severely affected by a deep-fade and or poor channel conditions; to cope with such difficulties Diversity Combining (DC) Hybrid ARQ (H-ARQ) is a viable technique, since it combines the several packet copies sent by a MT to create reliable packet symbols at the receiver. In this thesis we consider the use of FTN signaling for the uplink of broadband wireless systems employing SC-FDE based on the Iterative Block with Decision Feedback Equalization (IB-DFE) receiver with a simple scheduled access Hybrid Automatic Repeat reQuest (H-ARQ) specially designed taking into account the characteristics of FTN signals. This approach achieves a better performance than Nyquist signaling by taking advantage of the additional bandwidth employed of a root-raised cosine pulse for additional diversity. Alongside a Packet Error Rate (PER) analytical model, simulation results show that

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Proceedings Article•DOI•

Interleaver-Linked Receiver Beamforming with Transmitter Channel Equalization in TDD-IDMA-Based Random Access

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Yuto Muroki¹, Yotaro Murakami¹, Yoshihisa Kishiyama², Kenichi Higuchi¹•Institutions (2)

Tokyo University of Science¹, NTT DoCoMo²

01 Nov 2020

TL;DR: In this article, an interleaver-linked receiver beamforming method for time division duplex (TDD)-interleave division multiple access (IDMA)-based random access is proposed.

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Abstract: This paper proposes a novel interleaver-linked receiver beamforming method for time division duplex (TDD)-interleave division multiple access (IDMA)-based random access. When the number of receiver antennas at the base station is large in a massive multiple-input multiple-output (MIMO) scenario, the channel estimation accuracy per receiver antenna at the base station receiver is degraded due to the limited received signal power per antenna from the user terminal. This results in degradation in the receiver beamforming (BF) or antenna diversity combining and user detection. In the proposed method, a unique receiver BF vector applied at the base station is linked to each of the M interleavers prepared by the system. The user terminal selects an appropriate pair comprising a receiver BF vector and an interleaver in advance based on the channel estimation results in the downlink assuming channel reciprocity in a TDD system. Therefore, the per-receiver antenna channel estimation for receiver BF is not necessary in the proposed method. Furthermore, we also propose an application of a transmitter channel equalization to the proposed method for effective channel shortening in order to increase the orthogonal preambles for channel estimation prepared for each interleaver. Computer simulations results show that the proposed method greatly improves the accuracy of user detection and channel estimation which results in reducing the error rate compared to the conventional method that performs channel estimation at each antenna in a massive MIMO environment.

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References

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Open Access

More filters

Book•

Adaptive Filter Theory

[...]

Simon Haykin

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.

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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.

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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]....
[...]
...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 Article•DOI•

Analysis and Simulation of a Digital Mobile Channel Using Orthogonal Frequency Division Multiplexing

[...]

Jr. L.J. Cimini¹•Institutions (1)

Bell Labs¹

01 Jul 1985-IEEE Transactions on Communications

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.

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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.

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2,627 citations

"Frequency domain equalization for s..." refers background in this paper

...OFDM transmits multiple modulated subcarriers in parallel [ 1 ]....
[...]
...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 ]....
[...]

Book•

Adaptive filter theory (2nd ed.)

[...]

Simon Haykin¹•Institutions (1)

McMaster University¹

01 Mar 1991

2,447 citations

Journal Article•DOI•

BER sensitivity of OFDM systems to carrier frequency offset and Wiener phase noise

[...]

Thierry Pollet¹, M. Van Bladel¹, Marc Moeneclaey¹•Institutions (1)

Ghent University¹

01 Feb 1995-IEEE Transactions on Communications

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.

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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. >

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1,816 citations

Journal Article•DOI•

Polyphase codes with good periodic correlation properties (Corresp.)

[...]

D. Chu¹•Institutions (1)

Hewlett-Packard¹

01 Jul 1972-IEEE Transactions on Information Theory

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.

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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.

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