30 1 01 1 JOURNAL OF APPLIED SCIENCES Electroics ad Iformatio Egieerig Vol. 30 No. 1 Ja. 01 DOI: 10.3969/j.iss.055-897.01.01.007 OFDM 1, 1,, 1, 1 1. 400065. 400035 OFDMAF amlify ad forward...... P393.04 055-897(01)01-0039-06 Resource Otimizatio for Fairess ad Sum Rate radeoff i Multiuser OFDM-Based wo-way Relayig ANG Lu 1, LIU Ji 1, LI Guo-ju, CHEN Qia-bi 1, WANG Guag-yu 1 1. Key Laboratory of Mobile Commuicatio echology, Chogqig Uiversity of Posts ad elecommuicatios, Chogqig 400065, Chia. Deartmet of Commuicatio Commadig, Chogqig Commuicatio Istitute, Chogqig 400035, Chia Abstract: I OFDM-based cooerative two-way relay etworks, sum rate ad fairess amog user airs caot be achieved simultaeously whe these user-airs exchage their iformatio resectively via a amlify-adforward two-way relay. his aer rooses a ovel subotimal resource allocatio scheme to trade off the roortioal fairess ad the system sum rate. his scheme is divided ito two stes to maximize the sum rate of the system subject to the costraits of total ower ad roortioality amog user-air data rate. First, sub-carrier otimizatio is rocessed with equal ower amog every subcarrier to achieve roortioal fairess ad imrove the system sum rate. o further imrove the sum rate while maitaiig fairess, the total ower is allocated to every sub-carrier with a iterative ower allocatio algorithm. Simulatio demostrates that the roosed scheme of resource allocatio ca achieve good tradeoff betwee roortioal fairess ad system sum rate. Keywords: OFDM, two-way relayig, roortioal fairess, sub-carrier otimizatio, ower otimizatio. 4. [1. [-3 011-04-6 011-08-30 (No.011ZX03003-003-0) (No.6097070, No.61171111) (No.CSC009BA090) (No.KJ100514) (No.A011-) (No.A011-10) E-mail: tagl@cqut.edu.c E-mail cheqb@cqut.edu.c
40 30... (orthogoal frequecy divisio multile access, OFDM). OFDM OFDM. OFDM [4-6. [4-5 1 [6.. OFDM. [7. [8. [9 OFDMA. OFDM. 1 OFDM 1 M k B k (k 1,, M). OFDM N. (multile-access, MA) (broadcast, BC). MAOFDMA(orthogoal frequecy divisio multile access). h f B k B k x x B k B k, 1 OFDM Figure 1 System model for multiuser OFDM-based two-way relayig B k B k. B k k (k 1,, M) yk h x + B k fb k x B k + k (1) k (additive white Gaussio oise, AWGN). BC yk B k. R [10 ηk R ( h ) + f () + 1 (time divisio dulexig, DD) B k y η k h y k + (3) y B k η k f B k y k + B k (4) B k B k η k h x η k f x.. B k (chael state iformatio CSI) CSI CSI. B k y η k h B k f B k x B k + η k h k + (5)
1 OFDM 41 y B k η k f B k h x + η k f B k k + B k (6) B k γ γ B k γ γ B k R R h R f B k h + h + f (7) + 1 R h fb k f + h + f (8) + 1 k Rk 1 [ ( ) ( ) lb 1 + γ + lb 1 + γ (9) 1. t k {0, 1} k t k 1 t k 0. M 1. t k k1 OFDM M R t krk (10) k1 1 (10) t k. OFDM. P 1 subject to max {t k,, R, } R M t k 1 k1 M k1 1 t krk R 1 : R : : R k χ 1 : χ : : χ k M ( R + + ) B k P 1 k1 1 t k (11) P Rk k χ1 : χ : : χk R....1 (k, ) (k, ) P max {, R, } R k subject to + R + B k (1) [5 KK P 1 1 [1 + f 1 + f + [ 1 + h [ 1 + f B k [ 1 + h [ 1 + f B k (13) 1 + f + [ 1 + h [ 1 + f R (14) (15) (13) (15) (7) (8) B k γ γ B k γa k γb k γk 1 ( ) h f + h [ + f + 1 + [ h 1 + (16) f
4 30 P max Rk max γ k h fb k.. 1, arg max t,k γ k k (17) 0,. P 1 R1 : R : : Rk χ1 : χ : :χk 1 Rk 0 k Ω k S( S). for k 1 : M i arg max γk i ti k 1 i k Rk Ω k Ω k i S S i. 3 S arg mi k R k k arg χ k max γ j k j S k. Rk Ω k Ω k j S S j.. (16) (k, ) Rk. P 3 subject to max R 1 P 1 0 R k R1 : R : : Rk χ1 : χ : : χk (18) P 3. P 3 P 4 max R R k subject to P 1 0 1 (19) λ P 4 f(λ) max 0 L P 4 max 0 1 ( N ) Rk λ P 1 L P 4 P 4 ( N ) L P 4 Rk λ P 1 subject to 0 1 (0) (1) N f (λ) max 0 [R k λ () f (λ) f (λ) + λp (3) 1 g (λ) mi f (λ) (4) λ 0 (3) λ P 4 P R d g (λ ) R 0. d 0 [1. P 4 N [13 P 3. (4). N. λ [11 () P [ 1 λ ( ) h + f + h f (5)
1 OFDM 43 (x) + max {0, x}. λ [ ( + λ (t + 1) λ (t) + µ P ) (6) 1 t µ. µ t λ [14. λ (5) P. (13) (15) B k R.. P 3 R1 : R : : Rk χ1 : χ : : χk P 1 for k 1 : M R / k χk R χ 1 R / k χk R χ > 1 k. k τ P τp. τ τ 3. P R k. ( K R ) /( ( k Rk ) ) 3 F K 1 k1 χ k χ k. R1 : R : : Rk χ1 :χ : :χk F 1. 0.05 F ( K R ) /( ( k Rk ) ) K 0.95. F k1 χ k χ k 0.95 1 F > 0.95. F. P (13) (15) B k R. 3 5 MHz 64 OFDM. γ P ( γ P ). h v 1 / d l f v /(1 d) l v i i 1, 0 1. d 1 d d 0 1. l l 3. 4 5 P. R1 : R : R3 : R41:1:1:1... P Figure Achieved sum rate versus total ower 3 4 d 4 P 60 W.. 3 R1 : R : R3 : R41:1:1:1.. 4 R1 : R : R3 : R41:::..
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