THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. vol. 26, no. 7, Jul [1]. (array gain) (, precision) (Channel State

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1 THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE Jul.; 26(7), ISSN (Print)ISSN X (Online) M-PSK A Novel Dual-Layer Differential Equal Gain Transmission Technique Using M-PSK Constellations 김영주 서창원 Young-Ju KimChang-Won Seo 요약 -Advanced(-A), IEEE802.11ac,,. M,...,, 8. Abstract We propose a dual-layer differential equal-gain codebook design methodology for -Advanced(-A), IEEE802.ac, and radar system having multiple transmit and receive antennas, and make computer simulations to evaluate its link-level performaces. M-ary phase shift keying constellation is used as its codeword elements to utilize low-cost power amplifiers at mobile stations. Especially, the proposed codebook can meet radar systems requirement for the high-powered equal-gain transmission property. Due to the temporal correlation of the adjacent channel, the proposed differential codebook can quantize only the differential information of the channel instead of the whole channel subspace, which virtually increase the codebook size to realize more accurate quantization of the channel. The proposed codebook has the same properties of codebook that is, constant modulus, complexity reduction, and nested property. Computer simulations show that the proposed codebook performs better than the conventional 8-ary codebooks with the same amount of feedback information. Key words: Closed-Loop MIMO, Differential Codebook, -A, Spatial Multiplexing. 서론 Long-Term Evolution() -Advanced(-A) (multiple-input multiple-output) (College of Electrical & Computer Engineering, Chungbuk National University) Manuscript received June 11, 2015 ; July 2, 2015 ; Accepted July 8, (ID No ) Corresponding Author: Young-Ju Kim ( scw3738@hanmail.net) c Copyright The Korean Institute of Electromagnetic Engineering and Science. All Rights Reserved. 627

2 THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. vol. 26, no. 7, Jul [1]. (array gain) (, precision) (Channel State Information: CSI). (channel state information). Grassmannian (subspace packing) chordal [2],[3], (Singular Value Decomposition: SVD) Lloyd [4]. SVD (Maximum Ratio Transmission: MRT) (Equal Gain Transmission: EGT). EGT(Quantized EGT: QEGT) [5]. QEGT Grassmannian (scalar) (vector) [6],[7], MRT(quantized MRT, QMRT) (suboptimum). QEGT (constant modulus). (),. -A [8]. -A M-PSK. [9], M- PSK (constellation). M-PSK, trade-off [10][11]., (orthonormal). I., A, A A. (complex space), A A. AB A B A B A B Hadamard.. 시스템모델 -A.,. 1 MIMO.,. W W W (channel realization index) (time instant),,, W, W., ( ),. W W. y (1). 628

3 M-PSK 그림 1. MIMO Fig. 1. Closed loop MIMO system block diagram. y H W s n (1) H, H (independent and identically distributed: i.i.d.) 0, 1. n (Additive White Gaussian: AWG), 0, (power). (Signal-to-Noise Ratio: SNR). (Signal to Noise Ratio: SNR), H W s n 1., (2) 1 -. H H G (2) G 0, 1. H H. H. Jakes., 0, (, channel instant interval),,, ms.. 이중계층차분선부호화시스템 3-1 기존의차분코드북동작 WiMAX. MIMO, MIMO,, (, sphere) (spherical cap), Procrustes Gram-Schmidt [12]. -A release 10, 11 (duel), (adaptive) [13]. WiMAX m (transformation-based), [14]. 629

4 THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. vol. 26, no. 7, Jul (, sphere).,... [15]. W W W (3) W, (square) W. W, 0 (quasi-diagonal). (mutual information). [12]. [16], (spherical cap) (perturbation) (perturbed matrix) (unitary space) (project, ). (channel directional variation) [18].. W I W (4), (projection),. Procrustes Gram-Schmidt [17]. Grassmannian,, M-PSK. 3-2 제안하는차분코드북동작및설계. (5) W W. W W W (5), W (element by element) Hadamard, W., (inner product, ),. release-8,. (5). H, (precoder) W W. (6) (channel capaciy). arg max H W (6) M-PSK, [18] 2(a) 630

5 M-PSK (a) 그림 2. (a), (b) Fig. 2. (a) constellation, (b) constellation. (b). 16, 32, 64, 64 32, 2(b)., 32 W 5,,,. 5 throughput,. [22]., N=16, W. N 16, W chordal (b) 5,.. (6). 1.. 제안하는차분코드북의성능분석 Monte-Carlo. MIMO. 4, 2 4 MIMO. 4,. 1 Gauss-Markov, GHz. 1 kmhr kmhr, 0.999, [18]. Monte-Carlo achievable throughput. 2, 2,, 631

6 THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. vol. 26, no. 7, Jul 표 1. MIMO M-PSK Table. 1. Proposed M-PSK differential codebook in dual-layer. Index Codeword(Rank 1) Codeword(Rank 2) ,,., db. throughtput db., y throughput, x. 3, 4 2, kmhr, kmhr, db, db.,,. 5, 6 4, kmhr, kmhr 632

7 M-PSK 그림 3. kmhr, Fig. 3. Achievable throughput performance of various differential kmhr and. 7.4 그림 5. kmhr, Fig. 5. Achievable throughput performance of various differential kmhr and 그림 4. kmhr, Fig. 4. Achievable throughput performance of various differential kmhr and.. db, db. 3 6, 7.4 그림 6. kmhr, Fig. 6. Achievable throughput performance of various differential kmhr and

8 THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. vol. 26, no. 7, Jul Ideal EGT 5.35 그림 7. kmhr, Fig. 7. Achievable throughput performance of various differential kmhr and Ideal EGT 그림 8. kmhr, Fig. 8. Achievable throughput performance of various differential kmhr and.,. 7, 8 2 4, kmhr 1., db, db.. 결론 MIMO..,. References [1] 3GPP TS , Evolved Universal Terrestrial Radio Access(E-UTRA); Physical channels and modulation, Release [2] D. J. Love, R. W. Heath Jr., and T. Strohmer, "Grassmannian beamforming for multiple-input multiple- output wireless systems", IEEE Trans. Inform. Theory, 49, pp , [3] D. J. Love, R. W. Heath Jr, "Limited feedback unitary precodig for spatial multiplexing systems", IEEE Trans. Inform. Theory, 51, pp , [4] S. A. Jafar, S. Srinivasa, "On the optimality of beamforming with quantized feedback", IEEE Trans. Commun., 55, pp , [5] D. J. Love, R. W. Heath, "Equal gain transmission in multiple-input multiple-output wireless systems", IEEE Trans. Commun., 51, pp , [6] C. R. Murthy, B. D. Rao, "Quantization methods for eq- 634

9 M-PSK ual gain transmission with finite rate feedback", IEEE Trans. Signal Processing, 55, pp , [7] X. Zheng, Y. Xie, J. Li, and P. Stoica, "MIMO transmit beamforming under uniform elemental power constraint", IEEE Trans. Signal Processing, 55, pp , [8] "IEEE P802.16m-2008 draft standard for local and metropolitan area network", IEEE Standard m, [9] N. Y. Park, Y. J. Kim, "Performance analysis of duallayer differential precoding technique using constellation", J. KICS, vol. 38A, no. 5, pp , May [10] N. Y. Park, Y. J. Kim, "A new differential codebook design method using codebook for time correlated fading channels", in Proc. KICS Winter Conf. 2013, pp , Jan [11] X. Li, N. Y. Park, and Y. J. Kim, "Differential codebook for EGT systems over temporally correlated channels", in Proc. KICS Winter Conf. 2011, pp , Feb [12] T. Kim, D. J. Love, B. Clerckx, and S. J. Kim, "Differential rotation feedback MIMO system for temporally correlated channels", GLOBECOM IEEE, pp. 1-5, [13] R , WF on 8 Tx codebook, 3GPP TSG RAN WG1 62, [14] IEEE C802.16m-09/0058r3, Differential feedback for IEEE m MIMO schemes, [15] T. Kim, D. J. Love, and B. Clerckx, "MIMO systems with limited rate differential feedback for slowly varying channels", IEEE Trans. on Commun., pp , [16] J. Yang, D. B. Williams, "Transmission subspace tracking for MIMO systems with low-rate feedback", IEEE Trans. on Commun., pp , [17] G. H. Golub, C. F. V. Loan, Matrix Computation, 3rd ed., Johns Hopkins University Press, [18] Y. J. Kim, X. Li, T. J. Kim, and D. J. Love, "A combination lock-like differential codebook for temporally correlated channels", IET Electronics Letters, vol. 48, no. 1, pp , Jan System : () UM- TS : Purdue Univ : [ 주관심분야 ] -A, Distributed Antenna : () : [ 주관심분야 ], - A, MIMO 635