Transcription

1 ( ) 2009

2 CRC DS-CDMA OFDM MC-CDMA (Vector Coding) (OFDM) (E-SDM) DS-CDMA CCI AWGN i

3 3 MC-CDMA DS-CDMA MC-CDMA S/P MC-CDMA CP AMC SIR AMC TPC Vector Coding Vector Coding Modulation and Coding Scheme (MCS) MCS N max N min MMSE ii

4 DS-CDMA ( 2 ) MC-CDMA ( 3 ) ( 4 ) Vector Coding ( 5 ) A 104 A A A A A iii

5 CDMA OFDM MC-CDMA VSF-OFCDM WSSUS Vector Coding OFDM MIMO CCI ( ) BER (E s /N 0 = 5dB) ACS (E s /N 0 = 5dB) ACS E s /N BER E s /N 0 (7 users) BER E s /N 0 (7 users) BER (E s /N 0 = 5dB) ACS (E s /N 0 = 5dB) ACS E s /N BER E s /N 0 (7 users) MC-CDMA S/P MC-CDMA CP PBT iv

6 3.5 PBT (F d =8Hz) (MC-CDMA S/P ) (DS-CDMA,RAKE) ( ) ( ) SIR (AWGN) (HiperLAN/2 ) (AWGN) ( ) TPC AMC Vector Coding AMC ACCE ACCE VC MMSE PER MCS (VC) MCS (MMSE) N act (SNR=30dB) v

7 IEEE802.11a MCS MCS Set for Indoor and Outdoor Applications MCS Set vi

8 1990 web Mbps 10Mbps Mbps 2000 LAN AV LAN IEEE802.11b 11Mbps 54Mbps a/g 600Mbps n 300Mbps IMT-Advanced IEEE VHT (Very High Throughput) 1Gbps 1 ( ) 1 100Mbps 100Mbps ( ) LAN IEEE802.11a 8 MIMO (Multiple-Input Multiple-Output) IEEE802.11n 16 1

9 3 (3G) 3.5G 3.9G G CDMA 2 3 MC-CDMA (MultiCarrier Code Division Multiple Access) MC-CDMA 2

10 DS-CDMA (Direct Spread CDMA) RAKE MC-CDMA 4 4 NTT VSF-OFCDM (Variable Spreading Factor-Orthogonal Frequency and Code Division Multiplexing) MCS (Modulation and Coding Scheme) SNR (Signal to Noise Ratio) CRC (Cyclic Redundancy Check) MCS MCS 5 Vector Coding MIMO Vector Coding 1 CRC 6 3

11 1 1.1 DSL PC AV LAN LAN 1.1 1,000M 1Gbps s ] p [b 度速送伝 100M 10M 1M 100k a/g b 3G 2.5G n 3.5G 3.9G 10k 2G 1k 1990 年 1995 年 2000 年 2005 年 2010 年 携帯電話無線 LAN 1.1: (2G) PDC (Personal Digital Cellular) 9.6kbps 28.8kbps [1.1] 2 D-AMPS (Digital Advanced Mobile Phone System) 13kbps PDC D-AMPS 4

12 1 GSM (Global System for Mobile Communications) [1.2] GSM PDC GPRS (General Packet Radio Service) 115kbps GSM/GPRS GPRS IS-95 (cdmaone) [1.3] W-CDMA (Wideband Code Division Multiple Access) [1.4] [1.5] 3 (3G) 384kbps ITU (International Telecommunication Union) IMT-2000 (Inter Mobile Telecommunications ) 2Mbps 2G 2.5G 3G 3GPP (3rd GenerationPartnership Project) [1.6] 3.5G 3.9G W-CDMA TD-CDMA (Time Division - CDMA) UMTS (Universal Mobile Telecommunications System) 3G 3.5G Mbps HSDPA (High Speed Downlink Packet Access) [1.7] GPP-LTE (3rd Generation Partnership Project - Long Term Evolution) 3.9G [1.8] 100Mbps CDMA LAN 2Mbps b LAN 54Mbps a/g[1.9] DSL LAN 300Mbps n ( ) n 600Mbps [1.10] LAN IEEE WG (Working Group) 3GPP IMT-Advanced IEEE VHT (Very High Throughput) 1Gbps 1Gbps 1.1 LAN DS-SS (Direct Sequence - Spread Spectrum) OFDM (Orthogonal Frequency Division and Multiplexing) 5

13 1 DS-SS TDMA (Time Division Multiple Access) ASIC (FFT) OFDM OFDM 1 OFDM PAPR (Peak to Average Power Ratio) 3GPP-LTE OFDM 1.1: カテゴリ 2G 2.5G PDC GSM GPRS 名称 伝送速度 9.6kbps 28.8kbps 9.6kbps 171kbps 帯域幅 変調方式 ( 下り ) 50kHz DQPSK TDMA 200kHz GMSK TDMA アクセス方式 要素技術 IS-95(cdmaOne) 144kbps 1.25MHz QPSK DS-CDMA スペクトル拡散 3G CDMA Mbps 1.25MHz QPSK/16QAM DS-CDMA スペクトル拡散 UMTS (W-CDMA,TD-CDMA) 384kbps 5MHz QPSK DS-CDMA スペクトル拡散 3.5G HSDPA 14.4Mbps 5MHz QPSK/16QAM DS-CDMA スペクトル拡散 3.9G 3GPP-LTE 100Mbps (2010 年を予定 ) 20MHz QPSK/16QAM/64QAM OFDMA( 下り ) SC-FDMA( 上り ) OFDM MIMO IEEE802.11b 11Mbps 11MHz CCK CSMA スペクトル拡散 無線 LAN IEEE802.11a/g 54Mbps 20MHz BPSK/QPSK/16QAM/64QAM CSMA OFDM IEEE802.11n 300Mbps 20MHz BPSK/QPSK/16QAM/64QAM CSMA OFDM MIMO DS-SS OFDM MIMO (Multiple-Input Multiple-Output) 3GPP- LTE IEEE802.11n WiMAX MIMO MIMO MIMO IEEE802.16m IMT-Advanced 6

14 力電信送力電信送 時間周波数 力電信受力電信受 時間 周波数 1.2: 1.2 ( ) [1.11]

15 1 MCS (Modulation and Coding Scheme) (Adaptive Modulation and Coding:AMC) 1.3 SNR 16QAM, 符号化率 3/4 16QAM, 符号化率 1/2 QPSK, 符号化率 1/2 64QAM, 符号化率 2/3 時間 1.3: MCS MCS n MCS AMC SNR SNR MCS 1.4 8

16 1 スループット MCS3 MCS2 MCS1 MCS1 と 2 の切替え閾値 MCS2 と 3 の切替え閾値 SNR 1.4: SNR MCS SNR MCS 1.4 3GPP-LTE Capability 300Mbps MCS CQI (Channel Quality Information) OFDMA MCS

17 1 パラメータ 制御単位 切り替え基準 通信方式の選定 サブキャリア配置 全リソース共通 電力基準 ( 受信電力 SNR SIR) 最適方式を計算 サブキャリア数変調方式 リソース毎に個別 チャネル基準 ( チャネル容量 チャネル相関 ) 閾値による切り替え Ack 等による切り替え 符号化率 誤り基準 (CRC Ack) 送信電力 尤度情報 符号多重数 空間多重数 復号パス 1.5: AMC 1.5 MCS IEEE802.11a 8 MCS MCS 1.2: IEEE802.11a MCS No MCS 1 6Mbps BPSK, 1/2 2 9Mbps BPSK, 3/4 3 12Mbps QPSK, 1/2 4 18Mbps QPSK, 3/4 5 24Mbps 16QAM, 1/2 6 36Mbps 16QAM, 3/4 7 48Mbps 64QAM, 2/3 8 54Mbps 64QAM, 3/4 MCS 10

18 1 3GPP-LTE MCS [1.12] OFDM OFDM 3GPP-LTE OFDMA ( ) MCS n MIMO ( SNR SIR) ( ) (CRC Ack) SNR (Signal to Noise Ratio) SIR (Signal to Interference Ratio) [1.13] SNR SIR MIMO SNR 11

19 1 AMC MCS Ack Ack MCS 1 SNR MCS MCS 2 MCS CRC MCS SNR SNR SNR SNR SNR CRC (Cyclic Redundancy Check) CRC OK: SNR δ down db CRC NG: SNR δ up db δ down δ up (PER) δ down = 0.99dB δ up = 0.01dB PER CRC OK 1 CRC NG 12

20 1 PER SNR CRC OK CRC OK CRC Error CRC Error CRC OK MCS1 と MCS2 の切り替え閾値 MCS2 MCS1 時間 1.6: γ δ down γ δ up γ PER γ MCS DS-CDMA DS-CDMA IS-95 3G W- CDMA DS-CDMA 1.7 DS-CDMA 13

21 1 基地局 端末 ( ユーザ #1) ユーザ #1 ユーザ #2 ユーザ #K 変調 変調 変調 拡散 拡散 拡散 RF RF D D 2 逆拡散逆拡散逆拡散 位相補正位相補正位相補正 復調 D F-1 逆拡散 位相補正 RAKE 受信 (a) 端末 基地局 ユーザ #1 ユーザ #2 変調変調 拡散 拡散 RF RF RF D D F-1 逆拡散 逆拡散 逆拡散 位相補正位相補正 位相補正 ユーザ #1 復調 ユーザ #K 変調 拡散 RF ユーザ #K (b) 1.7: CDMA RAKE RAKE RAKE RAKE RAKE [1.14] Walsh [1.16] W-CDMA OVSF (Orthogonal Variable Spreading Factor) [1.15] Walsh 14

22 1 Gold [1.16] DS-CDMA [1.17][1.18] W-CDMA 2000 [1.19][1.20] 2 CAZAC (Constant Amplitude Zero Anto-Correlation) [1.21] CAZAC 3GPP-LTE CDMA IS-95 64kbps W-CDMA 384kbps QPSK W-CDMA OVSF [1.22] [1.23][1.24] [1.25] 2000 HSDPA 16QAM AMC HSPA DS-CDMA OFDMA OFDM PAPR (Peak to Average Power Ratio) CDMA 4G MC-CDMA OFCDM CDMA OFDM OFDM OFDM S/P P/S GI 15

23 1 IFFT GI 変調 S/P & RF RF P/S 付加 GI 除去 S/P FFT & P/S 等化 腹調 1.8: OFDM OFDM (FFT) (IFFT) CDMA OFDM 1960 ASIC OFDM CDMA RAKE OFDM DS-CDMA (Inter-carrier Interference:ICI) OFDM IQ ICI [1.26][1.27] OFDM PAPR PAPR 1990 [1.28]-[1.30] WiMAX 3GPP-LTE [1.31] OFDM LAN IEEE802.11a AMC 1 MCS OFDM MCS AMC [1.32] MCS [1.33] OFDM IFFT WiMAX 3GPP-LTE OFDMA 16

24 1 (Orthogonal Frequency Division Multiple Access) [1.34][1.35] MC-CDMA MC-CDMA (Multicarrier - CDMA) CDMA OFDM [1.36] CDMA MC-CDMA OFDM MC-CDMA 1.9 変調 IFFT GI 拡散 S/P & RF RF P/S 付加 GI 除去 S/P FFT & P/S 等化 逆拡散 腹調 符号 K-1 C K-1 (0) C K-1 (1) C K-1 (2) C K-1 (N-2) C K-1 (N-1) 符号 1 C 1 (0) C 1 (1) C 1 (2) C 1 (N) C 1 (N-1) 符号 0 C 0 (0) C 0 (1) C 0 (2) C 0 (N) C 0 (N-1) 周波数 1.9: MC-CDMA OFDM MC- CDMA CDMA 1990 MC-CDMA OFDMA [1.37] MC-CDMA [1.38] AMC NTT 4G VSF-OFCDM (Variable Spreading Factor - Orthogonal Code Division and Multiplexing) [1.39][1.40] MC-CDMA OFDMA 1( OFDMA) VSF-OFCDM SF time SF freq SF time SF freq 17

25 1 MC-CDMA SF freq SF time 768 carriers SF_freq frequency SF_time 拡散単位 768 time 1.10: VSF-OFCDM WSSUS (Wide Sense Stationary Uncorrelated Scattering)

26 1 Transmitter Receiver Propagation Delay Transmission Blocks Transmission Gap Multipath Tail time time Received Signal h(0) h(1) Transmission Block ( 1 block) x 0 x 1 x 3 x 4 x 0 x 1 x 3 x 4 x Nx-2 x Nx-1 x Nx-2 x Nx-1 Multipath Tail h(l-1) x 0 x 1 x 3 x 4 x Nx-2 x Nx-1 N y =N x +L : WSSUS h(l) L Transmission Gap h t (n) L 1 h t (n) = h(l) (1.1) N x x N y = N x +L 1 y y = Hx + n (1.2) l=0 n y H h(0) h(1) h(0) h(1) h(0) h(l 1). h(1).. 0 H =. 0 h(l 1)... h(0) 0 0 h(l 1)... h(1) h(l 1) (1.3) 19

27 (Vector Coding) MIMO H = UDV H (1.4) U V V U H D D N y N x D min(n x, N y ) H N x Vector Coding( VC) VC OFDM [1.41] 1.12 VC OFDM 1.3 [1.41] 1dB OFDM VC OFDM [1.42] R E B VC - flat VC - 2paths VC - 4paths VC - 8paths OFDM - flat OFDM - 2paths OFDM - 4paths OFDM - 8paths SNR [db] 1.12: Vector Coding OFDM 20

28 1 1.3: QPSK (OFDM ) dB 5Hz VC 1.2 VC 1988 [1.41] E-SDM (Eigenmode - Spatial Division Multiplexing) (OFDM) OFDM GI OFDM Cyclic Prefix GI N y N y ( GI N y = N x ) h(0) 0... h(l 1)... h(1) h(1) h(0) 0... h(l 1)... h(2) h(1) h(0) H o = h(l 1) h(l 2)... h(0) h(l 1) h(l 2)... h(0) h(l 1)... h(1) h(0) (1.5) 1.5 H o F H o K K D o D 1 2 o = F H o F H H H o H o = F H D o F (1.6) 21

29 1 1.2 OFDM F Ho H y o = D o s + F Ho H z o (1.7) OFDM VC V U VC OFDM OFDM OFDM VC VC OFDM Cyclic Prefix OFDM [1.43] (E-SDM) MIMO [1.44] MIMO Bell Laboratory [1.45] MIMO 1.13 MIMO WSSUS MIMO OFDM OFDM OFDM MIMO 3.9G 22

30 1 送信端末 h 00 受信端末 x 0 送信 RF h 10 h 01 受信 RF y 0 x 1 x 送信 RF h 11 H 受信 RF y 1 y 1.13: MIMO 1.13 MIMO y m = H m x m + n m (1.8) N t N r x m = [x 0, x 1,..., x Nt 1] y m = [y 0, y 1,..., y Nr 1] n m = [n 0, n 1,..., n Nr 1] n m (AWGN) OFDM N r N t ( N r N t ) H m h 0,0 h 0,1... h 0,Nt 1 h 1,0 h 1,1... h 1,Nt 1 H m = h Nr 1,0 h Nr 1,1... h Nr 1,N t 1 (1.9) ZF (Zero Forcing) MMSE (Minimum Mean Square Error) y m x m W m,zf = (H H m H m ) 1 H H m (1.10) W m,mmse = (H H m H m + σ 2 I) 1 H H m (1.11) σ 2 = E[ n 1 2 ] = E[ n 2 2 ] =... = E[ n Nr 2 ] MIMO (MLD:Maximum Likelihood Decision) [1.47] MLD [1.48] 23

31 1 MLD E-SDM (Eigenmode - Spatial Division Multiplexing) [1.49] E-SDM H m V m V m VC H m [1.50] H m = U m D m Vm H (1.12) U m N r N r V m N t N t D m N r N t V m U m y m = H m V m x m + n m U m y m = D m x m + U m n m (1.13) D m U m H m U m W m,zf W m,mmse U m ZF MMSE [1.51] IEEE802.11n MU-MIMO (Multi-user MIMO) [1.55] IMT- Advanced IEEE802.16m (OFDM ) OFDM MIMO OFDM n MCS OFDM MIMO [1.56][1.57] [1.58] CDMA [1.59] 24

32 1 2 章 3 章 4 章 5 章 目的 既存技術の課題 提案方式 効果目的 既存技術の課題 提案方式 効果 目的 既存技術の課題 提案方式 効果 目的 既存技術の課題 提案方式 効果 1.4: 干渉キャンセラにおいて ビタビ復号器の演算量を削減する レプリカ信号生成時 および干渉キャンセル後で 2 度のビタビ復号を必要とし レイテンシに問題が生じる レプリカ信号生成時のビタビ復号情報を用いて干渉キャンセル後のビタビ復号器の復号パスを適応的に制御する 伝搬路にも依存するが 60% 程度の演算量削減を達成 MC-CDMAのサブキャリア割り当てを適応的に行うことで スループットを改善する MC-CDMA では 逆拡散の際に直交性を補償する必要があり 等化方式が OFDM に比べて複雑であった また 従来では OFDM におけるサブキャリア割り当ての研究はあるが MC-CDMA ではなされていない 伝搬路状況に応じて 受信電力の高い順にサブキャリアを割り当てる 伝搬路に応じてサブキャリアを適応的に割り当てることで 簡易な等化方式でも DS-CDMA に比べてスループットを向上させることが可能となった 適応変調 符号化において 伝搬路の事前情報を用いずに MCS を制御する MCS を切り替えるための SIR 閾値を制御する際に 伝搬路の統計的な性質を知っておく必要があり 非現実的であった 上位の MCS に切り替える閾値 および下位の MCS に切り替える閾値について独立なターゲット誤り率を設定し CRC 結果においてのみ閾値を制御する 異なる伝搬環境においても 事前情報なしに最適に近いスループット特性を達成できた Vector Coding に AMC およびコードチャネル数制御を導入し スループットを改善する 時間領域にける行列について ZF や MMSE を行う研究は存在するが 通信路容量が最大にならない これを最大にするのは Vector Coding だが Vector Coding では利得の小さい符号チャネルが性能を劣化させる AMC とコードチャネル数制御を 同じ制御で実現する 手法は 4 章で用いたような CRC を用いた制御で 伝搬路の事前情報を必要としない MMSE と比較することで Vector Coding の位置づけを確認できた また AMC のみを用いた場合に比べて コードチャネル数制御によりスループットの向上が確認できた OFDM

33 1 適応制御によるによる演算量削減 適応制御によるによるスループットスループット向上 同期 アナログ歪み補正 伝搬路推定 追従 等化 尤度計算 誤り訂正復号 2 章 適応変調 符号化 (AMC) リソース共通 変調方式 符号化率独立制御 MCS 制御 リソース独立 ( ビット ローディング ) 4 章 変調方式 符号化率独立制御 MCS 制御 適応リソース割り当て 時間領域スケジューリング 周波数領域スケジューリング 空間領域スケジューリング 3 章 適応電力制御 リソース共通 ( パワー コントロール ) リソース独立 ( パワー ローディング ) 5 章 適応帯域幅制御 サブキャリア数制御 (OFDM ベース ) 拡散率制御 (CDMA ベース ) 適応多重数制御 空間ストリーム数制御 (MIMO ベース ) 符号チャネル数制御 (CDMA VC) 1.14: MCS [1.60] MCS

34 1 文献 文献 [1.61] パラレル型干渉キャンセラによる干渉低減 文献 文献 [1.62] キャンセラシステムにおいて レプリカ作成時に誤り訂正を適用 2 度のビタビ復号による演算量 ( レイテンシ ) が問題 2 章 DS-CDMA の干渉キャンセラに適応制御を導入し 誤り訂正復号器の演算量を削減 文献 文献 [1.65] ビタビ復号器の演算量削減 文献 文献 [1.67] OFDM におけるキャリアホール伝送 ( 他システムへの干渉回避 ) 文献 文献 [1.68] OFDM におけるサブキャリアごとのスケジューリング ( 性能向上 ) 文献 文献 [1.36] MC-CDMA が次世代の通信方式として期待 MC-CDMA におけるサブキャリアごとのスケジューリングは未検討 文献 文献 [1.66] MC-CDMA と DS-CDMA を比較 MC-CDMA は MLD で受信 3 章 MC-CDMA に適応制御を導入し 受信電力の低いサブキャリアを使わないように制御 簡易な受信方式で DS-CDMA と比較 比較 文献 文献 [1.69] マルチコード DS-CDMA 文献 文献 [1.70] 適応変調には SIR 閾値による切換えが有効 文献 文献 [1.25] CRC 結果による送信電力制御 文献 文献 [1.39][1.40] VSF-OFCDM の提案 文献 文献 [1.71] VSF-OFCDM における適応変調 SIR 閾値は固定 文献 文献 [1.73] HSDPA における適応変調 CRC 結果に応じて閾値を制御 伝搬路に応じた閾値設定が事前に必要 閾値は適応的に変動するが 上限閾値と下限閾値のオフセットを決めるのに伝搬路情報が必要 4 章 VSF-OFCDM に適応変調を導入 CRC 結果をもとに閾値を制御するが 伝搬路の事前情報を必要としない制御方法を提案 文献 文献 [1.52] Vector Coding の提案 文献 文献 [1.50] 空間領域の伝搬路行列に対して固有モード伝送を適用 (E-SDM) 文献 文献 [1.74] 時間領域の伝搬路行列に対して ZF や MMSE を適用 文献 文献 [1.41][1.42] Vector Coding の再評価 WSSUS 伝搬路におけるチャネル容量の最大化 比較 微弱な符号チャネルによる性能劣化 5 章 Vector Coding に適応変調を導入し 変調方式 符号化率のみならず固有チャネルの数を CRC 結果に応じて制御 MMSE と比較し Vector Coding の位置づけを明確化 1.15: 27

35 CDMA QPSK 16QAM MCS CDMA IS-95 HSPA [1.61] [1.62] PHS [1.63]-[1.65] 2 [1.65] ASIC 3GPP-LTE 3 MC-CDMA CDMA MC-CDMA [1.66] MC-CDMA DS-CDMA DS-CDMA MC-CDMA MLD 2 MC-CDMA MC-CDMA DS-CDMA [1.67] [1.68] OFDM MC-CDMA MC-CDMA OFDM DS-CDMA [1.69] 28

36 1 4 MC-CDMA VSF-OFCDM VSF-OFCDM MC-CDMA VSF-OFCDM 4G 100Mbps AMC AMC [1.71][1.72] VSF-OFCDM MCS SIR [1.70] CRC SIR [1.73] [1.73] MCS MCS ( ) MCS ( ) CRC 4 VSF-OFCDM 4G 5 Vector Coding (VC) MIMO VC VC CDMA OFDM VC ZF MMSE [1.74] VC 5 VC VC AMC ( ) VC 29

37 1 MIMO VC ( ) CRC MCS MCS AMC E-SDM OFDM [1.1],,, 2002 [1.2] GSM,, 2008 [1.3] Jerry D. Gibson, The Mobile Communications Handbook, CRC PRESS, 1996 [1.4] H. Holma, A. Toskala, WCDMA for UMTS, Wiley, [1.5] W-CDMA,, 2001 [1.6] 3GPP TS25.211, Physical channels and mapping of transport channels onto physical channels (FDD), [1.7] 3GPP TR25.848, Physical Layer Aspects of UTRA High Speed Downlink Packet Access, [1.8] 3GPP TS36.211, Evolved Universal errestrial Radio Access (E-UTRA) Physical Channels and Modulation, [1.9] IEEE Std T M -2007, [1.10] E.Perahia, and R.Stacey, Next Generation Wireless LANs, Cambridge University Press, 2008 [1.11],,,, [1.12] 3GPP TS36.213, Evolved Universal errestrial Radio Access (E-UTRA) Physical layer procedures, [1.13] K. Tsukakoshi, T. Kobashi, and Y. Kamio, Performance of DS-CDMA Adaptive Modulation System in a Multipath-Channel Environment, IEICE Trans. Commun., Vol.E86-B, No.2, February [1.14] J. Mitsugi, M. Mukai, and H. Tsurumi, Path-search algorithm introducing pathmanagement tables for a DS-CDMA mobile terminal, PIMRC 2002, Vol.2, pp , Sept

38 1 [1.15] Y. C. Tseng, C. M Chao, and S. L. Wu, Code placement and replacement strategies for wideband CDMA OVSF code tree management, GLOBECOM 2001, Vol.1, pp , Nov [1.16],,, [1.17] P. Patel and J. Holtzman, Analysis of Simple Successive Interference Cancellation Shame in a DS/CDMA System, IEEE J Select. Areas Commun., Vol.12, No.5, pp , June [1.18] M. Sawahashi, Y. Miki, H. Andoh, and K. Higuchi, Pilot Symbol-Assisted Coherent Multistage Interference Canceller Using Recursive Channel Estimation for DS- CDMA Mobile Radio, IEICE Trans., Commun., Vol.E79-B, No.9, pp , Septermber [1.19] K. Higuchi, K. Okawa, M. Sawahashi, and F. Adachi, Field Experiments on Pilot Symbol-Assisted Coherent Multistage Interference Canceller in DS-CDMA Reverse Link, IEICE Trans., Commun., Vol.E86-B, No.1, pp , January [1.20] N. Miki, S. Abeta, H. Atarashi, and M. Sawahashi, Multipath Interference Canceller Employing Multipath Interference Replica Generation with Previously Transmitted Packet Combining for Incremental Redundancy in HSDPA, IEICE Trans., Commun., Vol.E86-B, No.1, pp , January [1.21] Y. Wen, W. Huang, and Z. Zhang, CAZAC sequence and its application in LTE random access, Proc. of 2006 IEEE Information Theory Workshop (ITW 06), pp , October [1.22] F. Adachi, K. Ohno, A. Higashi, T. Dohi, and Y. Okumura, Coherent Multicode DS-CDMA Mobile Radio Access, IEICE Trans. Commun., vol. E79-B, no. 9, pp , Sept [1.23] S. Ariyavisitakul, Signal and interference statistics of a CDMA system with feedback power control - part II, IEEE Trans. Commun., Vol.42, pp , Feb./March/April [1.24] T. Dohi, M. Sawahashi, and F. Adachi, Performance of SIR based power control in the presence of non-uniform traffic distribution, Proc. of ICUPC 95, pp , Tokyo, Japan, Nov [1.25] K. Higuchi, H. Andoh, K. Okawa, M. Sawahashi, and F. Adachi, Experiments on adaptive transmit power control using outer loop for W-CDMA mobile radio, IEICE Technical Report, RCS98-18, pp.51-57, April [1.26] J. Tubbax, B. Come et. al, Compensation of IQ imbalance and phase noise in OFDM systems, IEEE Trans. on Wireless Commun. Vol.4, Issue 3, pp , May [1.27] Z. Qiyue, A. Tarighat, and A. Sayed, Joint compensation of IQ imbalance and phase noise in OFDM wireless systems, IEEE Trans. on Commun. Vol.57, Issue 2, pp , February

39 1 [1.28] S. Y. L. Goff, B. K. Khoo, C. C. Tsimenidis, and B.S. Sharif, A novel selected mapping technique for PAPR reduction in OFDM systems, IEEE Trans. on Commun., Vol.56, Issue 11, pp , November [1.29] Y. Guosen and W. Xiaodong, A hybrid PAPR reduction scheme for coded OFDM, IEEE Trans. on Wireless Commun., Vol.5, Issue 10, pp , Oct [1.30] H. Chen and H. Liang, Combined Selective Mapping and Binary Cyclic Codes for PAPR Reduction in OFDM Systems IEEE Trans. on Wireless Commun., Vol.6, Issue 10, pp , October [1.31] Y. Baoguo, K. B. Letaief, R. S. Cheng, and G. Zhigang, Channel estimation for OFDM transmission in multipath fadingchannels based on parametric channel modeling, IEEE Trans. on Commun., Vol.49, Issue 3, pp , March [1.32] K. Liu, F. Yin, W. Wang, and Y. Liu, An Efficient Greedy Loading Algorithm for Adaptive Modulation in OFDM Systems, IEEE PIMRC 2005, pp , Sept [1.33] Y. Li and G. Su, An Adaptive Modulation and Power-allocation Algorithm in OFDM System, IEEE ICCCAS 2004, pp , June [1.34] H. Jianwei, V. G. Subramanian, R. Agrawal, and R. A. Berry, Downlink scheduling and resource allocation for OFDM systems, IEEE Trans. on Wireless Commun. Vol.8, Issue 1, pp , Jan [1.35] Z. Chan, and G. Wunder, A Novel Low Delay Scheduling Algorithm for OFDM Broadcast Channel, IEEE GLOBECOM 2007, pp , Nov [1.36] N. Yee, J. P. Linnartz, and C. Fettweis, Multi-Carrier CDMA in indoor wireless radio network, IEICE Trans. Commun., vol. E77-B(7), pp , July [1.37] H. Rohling and R. Grunheid, Performance Comparison of Different Multiple Access Schemes for the Downlink of an OFDM Communication System, IEEE VTC 1997, Vol.3, pp , May [1.38] Adaptive modulation based MC-CDMA systems for 4G wireless consumer applications Chatterjee, S.; Fernando, W.A.C.; Wasantha, M.K.; Consumer Electronics, IEEE Transactions on Volume 49, Issue 4, Nov Page(s): [1.39] H. Atarashi, S. Abeta, and M. Sawahashi, Variable Spreading Factor-Orthogonal Frequency and Code Division Multiplexing (VSF-OFCDM) for Broadband Wireless Packet Access, IEICE Trans. Commun., Vol.E86-B, No.1, January 2003 [1.40] Y. Kishiyama, N. Maeda, K. Higuchi, H. Atarashi, M. Sawahashi, Field Experiments on Throughput Performance above 100 Mbps in Forward Link for VSF- OFCDM Broadband Wireless Access, IEICE Trans. Commun., Vol.E88-B, No.2, pp , Feb [1.41],, IEICE ( ), RCS , pp

40 1 [1.42],, Vector Coding OFDM, IEICE ( ), RCS , pp [1.43] Z. Wang, and G.B. Giannakis, Wireless multicarrier communications, IEEE Signal Processing Mag., vol.47, pp , Dec [1.44] D. Gesbert, M. Shafi, D. S. Shju, P. Smith, and A. Naguib, From theory to practice: An overview of MIMO space-time coded wireless systems, IEEE J. Select. Areas Commun., vol.21, No.2, pp , April [1.45] G. J. Foschini and M. J. Gans, Layered space-time architecture for wireless communication in a fading environment when using multielement antennas, Bell Labs Technical Journal, vol.1, pp.41-59, [1.46], MIMO, B, Vol.J86-B, No.9, pp , Sep [1.47] A. van Zelst, R. van Nee, and G. A. Awater, Space division multiplexing (SDM) for OFDM systems, Proc. IEEE Vehicular Technology Conference 2000-spring, pp , May [1.48] K. Higuchi, H. Kawai, N. Maeda, and M. Sawahashi, Adaptive selection of surviving symbol replica candidates based on maximum reliability in QRM-MLD for OFCDM MIMO multiplexing, Proc. IEEE Globecom2004, vol.4, pp , Nov [1.49] H. Sampath, P. Stoica, and A. Paulraj, Generalized linear precoder and decoder design for MIMO channels using the weighted MMSE criterion, IEEE Trans. Commun., vol.49, No.12, pp , Dec [1.50] G. H. Golub, and C. F. V. Loan, Matrix Computations. 3rd ed., Johns Hopkins University Press, Baltimore, [1.51],,, MIMO, B, Vol.J87-B, No.9, pp , Sep [1.52] J. T. Aslanis, S. Kasturia, G. P. Dudevoir, and J. M. Cioffi, Vector Coding for Partial Response Channels, MILCOM 88, Vol.2, pp , October 1988 [1.53] H. Z. Jafarian and S. Pasupathy, Complexity Reduction of the MLSD/MLSDE Receiver Using the Adaptive State Allocation Algorithm, IEEE Trans. on Wireless Commun., Vol.1, No.1, pp , Jan [1.54] C. Teekapakvisit, Yonghui Li, V.D. Pham, and B. Vucetic, Low Complexity Adaptive Iterative Receiver for Layered Space-time Coding CDMA Systems, Proc. of PIMRC 2005, pp [1.55] S. Zukang, C. Runhua, J. G. Andrews, R. W. Heath, and B. L. Evans, Sum Capacity of Multiuser MIMO Broadcast Channels with Block Diagonalization, IEEE Trans. on Wireless Commun., Vol.6, Issue 6, pp , June [1.56] A. N. Barreto, and S. Furrer, Adaptive bit loading for wireless OFDM systems, IEEE PIMRC 2001, Vol.2, pp.g88-g92, Sept

41 1 [1.57] S. Bergman,D. P. Palomar, and B. Ottersten, Optimal Bit Loading for MIMO Systems with Decision Feedback Detection, IEEE VTC 2009, pp.1-5, April [1.58] D. J. Love, and R. W. Heath Jr., OFDM power loading using limited feedback, IEEE Trans. on Vehicular Technology, Vol.54, Issue 5, pp , Sept [1.59] M. A. Khalighi, J. M. Brossier, G. V. Jourdain, and K. Raoof, Water filling capacity of Rayleigh MIMO channels, IEEE PIMRC 2001, Vol.1, pp.a155-a158, Sept [1.60] N. Miki, Y. Kishiyama, K. Higuchi, and M. Sawahashi, Optimum Adaptive Modulation and Channel Coding Scheme for Frequency Domain Channel-Dependent Scheduling in OFDM Based Evolved UTRA Downlink, IEEE WCNC 2007, pp , March [1.61] R. Kohno, H. Imai, M. Hatori, and S.Pasupathy, An Adaptive Canceller of Cochannel Interference for Spread Spectrum Multiple-Access Communication Networks in a Power Line, IEEE J Select. Areas Commun., Vol.8, No.4, pp , May [1.62] Y. Sanada and Q. Wang, A Co-Channel Interference Cancellation Technique using Orthogonal Convolutional Codes, IEEE Trans. on Commun., Vol.44, No.5, pp , May [1.63] K. Kwazoe, S. Honda, S. Kubota, and S. Kato, Universal-coding-rate Scarce State Transition Viterbi Decoder, IEEE ICC 1992, Vol.3, pp , June [1.64] S. Ping, Y. Yan, and C. Feng, An Effective Simplifying Shame for Viterbi Decoder, IEEE Trans. Commun. Vol.39, No.1, pp.1-3, Jan [1.65] T. Yamazato, I. Sasase, and S. Mori, A New Vitabi Algorithm with Adaptive Path Reduction Method, IEICE Trans. on Fun., Vol.E76-A, No.9, pp , Sep [1.66] S. Kaiser, OFDM-CDMA versus DS-CDMA: Performance Evaluation for Fading Channels, IEEE ICC 1995, Vol.3, pp , June [1.67],,,, OFDM,, [1.68] M. Wahlqvist, H. Olofsson, M. Ericson, C. Ostberg, and R. Larsson, Capacity comparison of an OFDM based multiple access system using different dynamic resource allocation, IEEE VTC 1997 Spring, Vol.3, pp , May [1.69] F. Adachi, K. Ohno, A. Higashi, T. Dohi, and Y. Okumura, Coherent Multicode DS-CDMA Mobile Radio Access, IEICE Trans. Commun., vol. E79-B, No. 9, pp , Sept [1.70] S. Falahati, A. Svensson, T. Ekman, and M. Sternad, Adaptive Modulation Systems for Predicted Wireless Channels, IEEE Trans. on Communications, Vol.52, No.2, pp , February 2004 [1.71] A. Harada, S. Abeta, and M. Sawahashi, Adaptive Radio Parameter Control Considering QoS for Forward Link OFCDM Wireless Access, IEEE VTC 2002 Spring, Vol.3, pp , May

42 1 [1.72] VSF-OFCDM, IEICE ( ), RCS , pp [1.73] J. Lee, R. Arnott, K. Hamabe, and N. Takano, ADAPTIVE MODULATION SWITCHING LEVEL CONTROL IN HIGH SPEED DOWNLINK PACKET AC- CESS TRANSMISSION, 3G Mobile Communication Technology Conference, May [1.74] Y. Takahashi, Y. Iwanami, and E. Okamoto, A time-domain block equalization scheme on SIMO frequency selective channels, IEEE Regicon 10 Conference

43 2 DS-CDMA CDMA ( ) % 2.1 CDMA (Co-Channel Interference:CCI) CCI (Multiuser Detection) [2.1] [2.2][2.3] CCI [2.4][2.5] [2.6] 36

44 2 DS-CDMA LAN [2.7][2.8] [2.7] DSP 1990 SST (Scarce State Transition) [2.9] [2.11] M- [2.12] [2.13] ACS (Add Compare Select) [2.7] 2 1 ACS CCI IS-95 Walsh ( ) Walsh PN 2.2 CCI 2.2 Wlash Walsh 37

45 2 DS-CDMA 2.1: De-spread & Correlation De-interleaving & Viterbi Decoding Received Signal Memory USER 1 De-spread & Correlation De-interleaving & Viterbi Decoding Encoding & Interleaving Re-spread USER 2 De-spread & Correlation De-interleaving & Viterbi Decoding Encoding & Interleaving Re-spread USER K De-spread De-interleaving Encoding & Correlation & Viterbi Decoding & Interleaving Re-spread 2.2: CCI 38

46 2 DS-CDMA M (Walsh ) 1/m (M = 2 m ) PN GP = T S /T C T S T C y(t) = K Pi W r (t τ i )C i (t τ i ) + n(t) (2.1) i=1 W r (t) r r = 1,..., M C i (t) i GP PN P i i τ i i (0 τ i T S ) n(t) N 0 /2[W/Hz] AWGN AWGN M k u 1 Z k (u) = T S 0 P = + T S TS TS 0 K P i=1 i k 1 + T S T S y(t)c k (t τ k )W u (t τ k )dt W r (t τ k )W u (t τ k )dt TS 0 C i (t τ i )C k (t τ k ) W r (t τ i )W u (t τ k )dt TS 0 n(t)c k (t τ k )W u (t τ k )dt = TS P T S W r (t τ k )W u (t τ k )dt K Ik u = P i=1 i k T S 0 + I u k + N u k (2.2) TS 0 C i (t τ i )C k (t τ k ) W r (t τ i )W u (t τ k )dt (2.3) 1 TS Nk u = n(t)c k (t τ k )W u (t τ k )dt (2.4) T S 0 39

47 2 DS-CDMA [2.8] V ar{i u k } = K i=1 i k γ ik E S 3GP 3 (2.5) E S = P T S γ ik k i PN γ ik 3GP 2 [2.14] V ar{n u k } = N 0 2 (2.6) Walsh u u = r { ES + Ik u Z k (u) = + N k u u = r Ik u + N k u u r (2.7) Z k (u) d [2.7] P d n1 = Q ( ) d SNRn1 2 (2.8) SNR n1 SNR n SNR n1 = 1 K 1 GP + N 0 2E s (2.9) K Q(t) Q Q(t) = 1 2π P e n t d free +3 exp( x2 )dx (2.10) 2 d=d free d A d P d n1 (2.11) A d d SNR SNR n2 SNR n2 = 1 2P e n K 1 GP + N 0 2E s (2.12) 40

48 2 DS-CDMA 2.12 P e n d free +3 d=d free B d P d n2 (2.13) B d d is the total number of nonzero information bits on all d free P d n2 SNR n2 P d n2 = Q ( ) d SNRn2 2 (2.14) Walsh 1 ( ) AWGN (T h1) P (Z k (u) > T h1 u r) 0 Z k (u) T h t 5 t T h1 2 2 t t ACS 41

49 2 DS-CDMA 2.3: ( ) 2.4: 1 2.5: 2.6: (T h2) P (Z k (u) < T h2 u = r) 0 Z k (u) < T h2 2.6 t 4 t 5 01 Walsh T h2 42

50 2 DS-CDMA ACS ACS 2.7 ACS 2 2 ACS (ACS ) = 1 (ACS ) (ACS ) (2.15) ACS ACS ACS (ACS ) = ( ) ( ) (2.16) 2.7: 2.1: Constraint Length 4 Coding Rate 1/3 Spread Sequence long PN sequence Processing Gain Packet Length 192 bit Bit Rate 64 kbps Noise AWGN 43

51 2 DS-CDMA AWGN 2.1 IS-95 AWGN AWGN (BER) T h1 T h2 1 T h1 2 T h2 2.9 ACS BER ACS T h1 T h ACS E s /N 0 T h1 T h % 27 20% ACS E s /N 0 T h1 T h2 E s /N 0 E s /N 0 ACS E s /N 0 ACS 2.11 BER E s /N 0 (ACS ) 3 0.3dB 2.10 ACS 44

52 2 DS-CDMA 2.8: BER (E s /N 0 = 5dB) 2.9: ACS (E s /N 0 = 5dB) 2.10: ACS E s /N : BER E s /N 0 (7 users) Hz 2.12 No Fading AWGN

53 2 DS-CDMA 10dB 10dB AWGN BER ACS 3 T h1 T h ACS E s /N BER E s /N AWGN ( 2.10) E s /N 0 ACS ACS 0.5-1dB 3 ACS 60% E s /N 0 80% ACS AWGN : BER E s /N 0 (7 users) 46

54 2 DS-CDMA 2.13: BER (E s /N 0 = 5dB) 2.14: ACS (E s /N 0 = 5dB) 2.15: ACS E s /N : BER E s /N 0 (7 users)

55 2 DS-CDMA E s /N dB 80% ASIC LAN WiMAX (64 ) [2.15] LDPC[2.16] [2.17] 2.6 [2.1] S. Verdu, Minimum Probabirity of Error for Asynchronous Gaussian Multiple- Access Channels, IEEE Trans. Inform. Theory, Vol.IT-32, No.1, pp.85-96, January [2.2] A. Kajiwara and M. Nakagawa, Crosscorrelation Cancellation in SS/DS Block Demodulator, IEICE Transact., Vol.E74, No.9, pp , September [2.3] A. Duel-Hallen, Decorrelating Decision-Feedback Multiuser Dtector for Synchronous Code-Dvision Multiple-Access Channel, IEEE Trans. on Commun., Vol.41, No.2, pp , February [2.4] R. Kohno, H. Imai, M. Hatori, and S. Pasupathy, An Adaptive Canceller of Cochannel Interference for Spread Spectrum Multiple-Access Communication Networks in a Power Line, IEEE J Select. Areas Commun., Vol.8, No.4, pp , May [2.5] P. Patel and J. Holtzman, Analysis of Simple Successive Interference Cancellation Shame in a DS/CDMA System, IEEE J Select. Areas Commun., Vol.12, No.5, pp , June [2.6] S. LIN and D. J. COSTELLO, Error Control Coding:Fundamentals and Applications, Prentice Hall 1983 [2.7] Y. Sanada and Q. Wang, A Co-Channel Interference Cancellation Technique using Orthogonal Convolutional Codes, IEEE Trans. on Commun., Vol.44, No.5, pp , May [2.8] Y. Sanada and Q. Wang, A Co-channel Interference Cancellation Technique using Orthogonal Convolutional Codes on Multipath Rayleigh Fading Channel, IEEE Trans. on Vehicular Technology, Vol.46, No.1, pp , Feb [2.9] K. Kwazoe, S. Honda, S. Kubota, and S. Kato, Universal-coding-rate Scarce State Transition Viterbi Decoder, IEEE ICC 1992, Vol.3, pp , June [2.10] S. Ping, Y. Yan, and C. Feng, An Effective Simplifying Shame for Viterbi Decoder, IEEE Trans. Commun. Vol.39, No.1, pp.1-3, Jan

56 2 DS-CDMA [2.11] T. Yamazato, I. Sasase, and S. Mori, A New Vitabi Algorithm with Adaptive Path Reduction Method, IEICE Trans. Fundamentals., Vol.E76-A, No.9, pp , Sept [2.12] J. B. Anderson and S. Mohan, Sequential coding algorithums:a Survey and cost analysis, IEEE Trans. Commun., COM-32, pp , Feb [2.13],,,, M-, SST94-6, pp.7-12, [2.14] S. Tachikawa, Characteristics of M-ary/Spread Spectrum Multiple Access Communication Systems using Co-Channel Interference Cancellation Techniques, IEICE Trans. on Commun., Vol.E76-B, No.8, pp , August [2.15] C. Berrou, A. Glavieux, and P. Thitimajshima, Near Shannon limit error-correcting coding and decoding: Turbo codes, IEEE ICC 1993, pp , May [2.16] R. G. Gallager, Low-Density Parity-Check Codes. Cambridge, M.I.T. Press, [2.17] C. M. Vithanage, P. M. A. P. Rajatheva, and E. Shwedyk, Performance of Turbo Equalized Space-time Coded Signals with Reduced Complexity Receiver Using M Algorithm, IEEE VTC 2004 Spring, Vol.2, pp , May

57 3 MC-CDMA 3G DS-CDMA DS-CDMA RAKE MC-CDMA RAKE MC-CDMA MC-CDMA DS-CDMA RAKE 3.1 3G DS-CDMA [3.1]-[3.5] DS-CDMA 3G 384kbps 2Mbps LAN 3GPP-LTE OFDM 1 DS-CDMA OFDM CDMA OFDM MC-CDMA[3.6][3.7] MC-CDMA VSF-OFCDM 4G OFCDM OFDM [3.8] OFCDM MC-CDMA DS-CDMA RAKE 50

58 3 MC-CDMA [3.9] MC-CDMA DS-CDMA [3.9] DS-CDMA RAKE MC-CDMA MC-CDMA ( ) DS-CDMA MC-CDMA DS-CDMA MC-CDMA DS-CDMA DS-CDMA DS-CDMA ( ) Walsh ( ) PN( Pseudo Random) PN [3.10] DS-CDMA W-CDMA DS-CDMA RAKE [3.11]

59 3 MC-CDMA MC-CDMA S/P MC-CDMA CDMA IDFT (Inverse Descrete Fourier Transform) 2 IFFT (Inverse Fast Fourier Transform) 2 MC-CDMA 3.1 MC- CDMA ( S/P ) ( )OFDM RAKE MC-CDMA MC-CDMA CP u C PG-1 (i) u C0 C 0 (i) 符号化データ time S/P IFFT P/S u C PG-1 (i) u C0 C 0 (i) 3.1: MC-CDMA S/P 3.1 IFFT u [3.7] s u sp(t) = + i= P G 1 n=0 P G 1 m=0 3.1 b u n(i) c u m(i)p c (t mt c it s) exp{j2π(f 0 +(n P G/2) f)t} (3.1) T c P G (=OFDM ) P G T s T s T s = P G T s 52

60 3 MC-CDMA b u n(i) u n i c u m(i) u m f 0 f(= 1/T c ) p c (t) = 1 (0 t T c ), p c (t) = 0 (otherwise) MC-CDMA CP MC-CDMA CP CDMA MC-CDMA 3.2 IFFT MC-CDMA CP u u C 0 (i) u C 1 (i) 符号化データ time Copier u C 2 (i) IFFT P/S u C PG-1 (i) 3.2: MC-CDMA CP [3.7] s u cp(t) = + i= P G 1 n=0 b u (i) c u n(i)p c (t it c ) exp{j2π(f 0 + (n P G/2) f)t} (3.2) b u (i) u i

61 3 MC-CDMA QPSK S/P CP 2 IFFT FFT 54

62 3 MC-CDMA S/P Convolutional Encoder & Interleaver QPSK Mod. S/P or Copy Spread Spread IFFT & P/S Code Channel 1 Information from the receiver Frequency Controller (a) Transmitter FFT Equalizer De-spread De-spread P/S or Combiner QPSK Demod. De-interleaver & Viterbi Decoder P/S Code Channel 1 Frequency Controller Frequency Assignment Information (b) Receiver 3.3: S/P MC-CDMA u 3.1 i=0 ( 0 t T s) u s(t) = P G 1 n=0 P G 1 m=0 b n c m p c ( t) exp(j2πf n t) (3.3) p c ( t) = p c {t mt c } f n = f 0 + (n P G/2) f s(t) 55

63 3 MC-CDMA OFDM L 1 h(t) = h l δ(t τ l ) (3.4) l=0 h l τ l l L 3.4 r(t) r(t) = (s h)(t) = = L 1 l=0 P G 1 n=0 P G 1 n=0 P G 1 m=0 P G 1 m=0 b n c m p c ( t) exp{j2πf n (t τ l )} H k b n c m p c ( t) exp(j2πf n t) (3.5) H n L 1 H n = h l exp( j2πf n τ l ) (3.6) l=0 r(t) f 0 [3.7] r (t) = P G 1 n=0 P G 1 m=0 H n b n c m p c ( t) exp{j2π(n P/2)t/T s} + z(t) (3.7) z(t) AWGN (Additive White Gaussian Noise) n m FFT r n = 1 Tc r (t) exp{ j2π(n P/2)t/T T s}dt c CP 0 = H n b n c m + z n (3.8) r n = H n b c n + z n (3.9) S/P CP RAKE (Partial Bandwidth Transmission:PBT) 3.4 PBT FDD (Frequency Division Duplex) 56

64 3 MC-CDMA P G PBT 3.4: PBT OFDM [3.12] R ofdm = 2P P + 1 R sc (3.10) R sc R ofdm OFDM P OFDM sinc 2 OFDM PBT 3.10 W-CDMA 3.84MHz 5MHz(2 ) IEEE802.11b 11MHz 22MHz 3.10 OFDM g 1/2 ( b ) 57

65 3 MC-CDMA PBT PBT (Least Square) 3.5: PBT P G 1-1 P G 1 1 P G 1 λ (packets/time units) k p k p k = e λ λ k. (3.11) k! ID ID

66 3 MC-CDMA 12 2 ] B d [ r e w o P d e iv e c e R Ideal Estimation Packet 3.6: (F d =8Hz) kbps QPSK BPSK DS-CDMA MC-CDMA 64 DS-CDMA MC-CDMA [3.1] MC-CDMA 3.10 DS-CDMA MC-CDMA MC-CDMA DS-CDMA MC-CDMA DS-CDMA QPSK 16QAM 64QAM 59

67 3 MC-CDMA OFDM [3.5] DS-CDMA 4 8Hz DS-CDMA MC-CDMA OFDM BCH <Modulation> Data Spreading Data Rate Number of Users 4 <Spreading Code> Short Code Long Code Processing Gain 64 Coding for data Coding for Header Packet Length Dopplar Frequency 3.1: Coherent QPSK BPSK 64 N kbps (N: Number of Code Channels) Hadamard Codes (64 period) Partial M Sequence ( period) Convolutional Code & Soft Decision Viterbi Decoding (Constraint Length 7, Coding Rate 1/3) BCH(15,7) & Repetition Code (3 times) 10 msec 8.0Hz MC-CDMA S/P DS-CDMA(RAKE ) (BER) No PBT 1 PBT PBT 2 LS Least Square Ideal est PBT PBT 2dB ( 3dB) PBT 60

68 3 MC-CDMA 4 PBT 1 3.7: (MC-CDMA S/P ) 3.8: (DS- CDMA,RAKE) 3.9: 61

69 3 MC-CDMA 3.9 DS-CDMA(RAKE ) MC-CDMA S/P CP (PER) RAKE 4 63 Traffic=1.0 (Traffic=1.0) PER MC-CDMA DS-CDMA RAKE 1% E b /N 0 S/P 5dB CP 4dB MC-CDMA S/P CP CP dB (0 ) (63 ) 5dB S/P 6 ] B d [ r e w o P d e liz a m r o N Subcarrier Index 3.10: Traffic MC-CDMA 62

70 3 MC-CDMA 3.11: 3.12: 63

71 3 MC-CDMA 3.5 MC-CDMA DS-CDMA RAKE MC-CDMA DS-CDMA RAKE MC-CDMA 2 S/P CP CP MC-CDMA OFCDM DS-CDMA [3.13] PAPR OFDM CDMA DS-UWB ZigBee VSF-OFCDM 4G IMT-Advanced LTE-Advanced IEEE802.16m OFDMA DS-CDMA 2 P i (i = 0, 1, N 1) t i i N 2 R(t) s 0 = s 3 = γ 0 = n n t 0 j s 1 = t 1 j s 2 = j=1 n t 3 j s 4 = j=1 n P j t 0 j γ 1 = j=1 j=1 n j=1 t 4 j n P j t 1 j γ 2 = n j=1 j=1 j=1 t 2 j n P j t 2 j 64

72 3 MC-CDMA Γ = (ns 2 s 4 + 2s 1 s 2 s 3 ) (s s 2 1s 4 + ns 2 3) a 0 = {(γ 0 s 2 s 4 + γ 1 s 2 s 3 + γ 2 s 1 s 3 ) (γ 2 s γ 0 s γ 1 s 1 s 4 )}/Γ a 1 = {(nγ 1 s 4 + γ 0 s 2 s 3 + γ 2 s 1 s 2 ) (γ 1 s γ 0 s 1 s 4 + nγ 2 s 3 )}/Γ a 2 = {(nγ 2 s 2 + γ 0 s 1 s 3 + γ 1 s 1 s 2 ) (γ 0 s nγ 1 s 3 + nγ 2 s 2 1)}/Γ R(t) = a 0 + a 1 t + a 2 t 2 (3.12) [3.1] F. Adachi, K. Ohno, A. Higashi, T. Dohi, and Y. Okumura, Coherent Multicode DS-CDMA Mobile Radio Access, IEICE Trans. Commun., vol. E79-B, no. 9, pp , Sept [3.2],,,, DS-CDMA, IEICE ( ), RCS95-79, pp [3.3] T. Dohi, Y. Okumura, A. Higashi, K. Ohno and F. Adachi, Experiments on Coherent Multicode DS-CDMA, IEICE Trans. Commun., vol. E79-B, no. 9, pp , Sept [3.4],,,, DS-CDMA, IEICE ( ), RCS95-80, pp [3.5],,,, DS-CDMA, IEICE ( ), RCS96-14, pp [3.6],,, IEICE ( ), RCS96-48, pp [3.7] N. Yee, J. P. Linnartz and C. Fettweis, Multi-Carrier CDMA in indoor wireless radio network, IEICE Trans. Commun. vol. E77-B(7), pp , July [3.8] M. Yoshida and A. Sugitani, A Comparison of OFCDM and Segmented-OFDM in Broadband MIMO Downlink Channel, IEEE WCNC 2004, Vol.2, pp , March [3.9] S. Kaiser, OFDM-CDMA versus DS-CDMA: Performance Evaluation for Fading Channels, IEEE ICC 1995, pp , June

73 3 MC-CDMA [3.10],, DS-CDMA RAKE, IEICE ( ), RCS95-98, pp [3.11] A. Higashi, T. Taguchi and K. Ohno, Performance of coherent detection and RAKE for DS-CDMA uplink channels, IEEE PIMRC 1995, pp , Sept , 1995, Toronto, Canada. [3.12] E. A. Sourour and M. Nakagawa, Performance of Orthogonal Multicarrier CDMA in a Multipath Fading Channel, IEEE Trans. on Commun., vol. 44, no. 3, pp , March [3.13] L. Mailaender, Complexity Comparison of OFDM and CDMA for Wideband Communication Systems, IEEE VTC 2006 Fall, pp.1-5, Sept

74 4 (AMC) AMC MCS MCS AMC MCS MCS (TPC) AMC TPC 4.1 LAN (Adaptive Modulation and Coding:AMC) [4.1]-[4.3] a n G HSDPA 3GPP-LTE 4G 1Gbps 100Mbps ARQ[4.4]-[4.7] AMC AMC OFDM MCS (Modulation and Coding Scheme) AMC MCS 1.3 SNR SIR 1 [4.8] MCS SIR MCS 1.3 SIR 67

75 4 ( ) [4.9] HSDPA CRC SIR MCS MCS ( ) MCS ( ) CRC MCS TPC (Transmission Power Control) MCS TPC TPC CRC 4G VSF-OFCDM[4.11] [4.12] VSF-OFCDM AMC [4.10] MCS 4G ARQ MCS 4.2 AMC MCS MCS MCS MCS MCS [4.10] VSF-OFCDM MCS MCS1 MCS3 64QAM MCS(n) MCS n = 1, 2,..., N N MCS MCS MCS(1) MCS MCS(N) 4.1 N=4, MCS(1)=MCS4, MCS(2)=MCS5, MCS(3)=MCS6, MCS(4)=MCS7 N=3, MCS(1)=MCS1, MCS(2)=MCS2, MCS(3)=MCS3 68

76 4 4.1: MCS Set for Indoor and Outdoor Applications MCS # Modulation Coding Rate Condition MCS7 64QAM R = 3/4 Indoor MCS6 16QAM R = 5/6 Indoor MCS5 16QAM R = 1/2 Indoor MCS4 QPSK R = 3/4 Indoor MCS3 16QAM R = 3/4 Outdoor MCS2 QPSK R = 3/4 Outdoor MCS1 QPSK R = 1/2 Outdoor MCS SIR 4.1 SIR MCS(1) MCS(2) SIR MCS(2) MCS(3) SIR MCS(2) MCS MCS(1) MCS(2) MCS(2) MCS(3) SIR [4.9] 4.1 トップールス AMC 時のスループット MCS2 MCS3 MCS1 最適な 下限閾値 最適な 上限閾値 SIR 4.1: ( ) 69

77 4 トップールス AMC 時のスループット MCS2 MCS3 MCS1 下限閾値 上限閾値 SIR 4.2: ( ) 4.3 CRC SIR CRC OK : SIR δ amc down CRC Error : SIR δ amc up PER (Packet Error Rate) 0.01 δdown amc δup amc 0.01dB 0.09dB CRC Error 99 CRC OK PER=0.01 PER 0.01 δdown amc =0.02dB δamc up =1.98dB PER=x δ amc down = x γ [db] δ amc up = (1.0 x) γ [db] (4.1) γ γ γ 1 CRC MCS MCS 2 1 MCS MCS 1 70

78 4 MCS MCS MCS MCS(n) SIR th (n) SIR th (n 1) SIR th (n) MCS(n) MCS(n+1) SIR th (n 1) MCS(n) MCS(n-1) MCS(n) MCS(n+1) SIR th (n) MCS(n+1) MCS(n) MCS(n) SIR th (n) CRC OK SIR th (n) δdown amc = 0.01 [db] (4.2) CRC Error SIR th (n) δ amc up = 0.99 [db] (4.3) SIR th (n 1) CRC OK SIR th (n 1) δdown amc Max thpt(n 1) = Max thpt(n) [db] (4.4) CRC Error SIR th (n 1) δup amc Max thpt(n 1) = 1.0 Max thpt(n) [db] (4.5) Max thpt(n) MCS(n) MCS SIR mes > SIR th (n) MCS(n) MCS(n+1) SIR mes < SIR th (n 1) MCS(n) MCS(n-1) MCS SIR mes SIR 0.01dB 0.99dB PER 0.01 MCS PER 0.01 MCS SIR MCS(2) 10Mbps MCS(1) 4Mbps MCS(2) 4Mbps MCS(1) MCS(1) 4Mbps MCS(2) 71

79 4 MCS(2) 4Mbps PER δ down δ up 0.4dB 0.6dB MCS(3) SIR th (3) SIR th (2) MCS(2) SIR th (2) MCS(3) MCS(2) SIR th (2) PER AMC CDMA (TPC) TPC 1. ( ) 2. AMC MCS MCS(1) AMC MCS(2) TPC MCS TPC TPC MCS MCS MCS(1) SIR SIR MCS MCS(N) SIR MCS MCS MCS(1) SIR th (0) MCS MCS(N) SIR th (N) SIR th (0) TPC SIR th (N) TPC MCS(n = 2, 3,..., N 1) TPC MCS(1) SIR mes < SIR th (0) tpc MCS(N) SIR mes > SIR th (N) tpc SIR th (0) SIR th (N) MCS(1) CRC Error SIR th (0) δ tpc(0) up 72

80 4 MCS(1) CRC OK SIR th (0) δ tpc(0) down MCS(N) CRC Error SIR th (N) δ tpc(n) up MCS(N) CRC OK SIR th (N) δ tpc(n) down δ δ tpc(0) up = δ tpc(0) down = 0.5dB δ tpc(n) up = 0.99dB and δ tpc(n) down = 0.01dB MCS 50% MCS 99% VSF-OFCDM[4.11][4.12] ARQ Chase Combining[4.13] MCS SIR MCS MCS ARQ ( ) 1 MCS ARQ 1 VSF-OFCDM MCS 3GPP [4.14] VSF-OFCDM ( ) [4.12] HiperLAN/2 [4.15] 5Hz [4.10] 12 1dB 80Hz 73

81 4 1.25MHz SF 2 300kHz Transmitter Data Generation Turbo Coding Puncturing Adaptive Modulation Transmitted Signal IFFT & GI Insertion Scrambl ing Pilot Symbol Insertion 2-dimension Spreading & Other users Multiplexing Gain Inter- leaving S/P Reveiver Feedback Information of TPC SIR Measure Feedback Information of AMC Received Signal GI Removal & FFT De- scrambling Pilot Data Channel Estimation Coherent Detection De- spreading De- interleaving P/S Threshold Control Data Verification Turbo Decoding De- puncturing De- mapping Feedback Information of H-ARQ 4.3: 74

82 4 Bandwidth 4.2: Num. of Subcarriers 768 Symbol Duration (Data + GI) [MHz] [usec] [usec] SF Indoor: 16 (8 x 2) (SF time x SF freq) Outdoor: 32 (8 x 4) No. of users Indoor case: 1 Outdoor case: 8 Feedback Information (Both AMC and ARQ) Feedback Delay (Both AMC and ARQ) H-ARQ method MCS Set (See Table 4.1) Channel Model Channel Estimation Synchronization Error Free 1 packet Chase Combining Indoor: MCS(4),(5),(6),(7) Outdoor: MCS(1),(2),(3) AWGN (single static path) Indoor: HiperLAN/2 Model (F d = 5Hz) Outdoor: Exponential Model (F d = 80Hz, Num.of paths = 12, Delay Spread = 0.21 [usec]) Pilot Aided (frequency tone) Ideal SIR 4.4 VSF-OFCDM SIR VSF-OFCDM OFCDM SIR r n,m n m 0 3 k (k = 0, 1,..., 47) SIR 75

83 4 P S (k) P I (k) SIR mes = 47 k=0 P S (k) P I (k) (4.6) P S (k) P I (k) P S (k) = R(k) 2 (4.7) P I (k) = 1 64 R(k) = (k+1) n=16k+1 16(k+1) n=16k+1 m=0 {r n,m R(k)} 2 (4.8) 3 r n,m (4.9) pilot Data pilot Data pilot 16 Carriers No Use No Use 768 Carriers No Use From previous packet 1 Packet r r r r 1,1 1,2 1,3 1,4 To From next next packet packet 16 r r r r 16,1 16,2 16,3 16, : SIR AWGN HyperLAN/2 E S /N 0 MCS 4.1 MCS4 MCS7 64QAM

84 4 MCS SIR MCS SIR AMC SIR SIR Throughput [ Mbps ] MCS4 MCS5 MCS6 MCS7 Proposed 30 ] s p b M [ 20 t u p g h u ro T10 MCS4 MCS5 MCS6 MCS7 Proposed E S / N 0 [ db ] E / N S 0 [ db ] 4.5: (AWGN) 4.6: (HiperLAN/2 ) MCS AWGN 8 AMC ARQ QPSK MCS 4.1 MCS1 MCS3 16QAM MCS 77

85 4 Throughput [ Mbps ] MCS1 MCS2 MCS3 Proposed 10 ] s p b 8 M [ t u 6 p g h u ro 4 T MCS1 MCS2 MCS3 Proposed E S / N 0 [ db ] E / N S 0 [ db ] 4.7: (AWGN) 4.8: ( ) AMC TPC 4.9 AMC TPC TPC 80Hz AMC TPC 4.9 E S /N 0 MCS1 E S /N 0 MCS3 E S /N 0 TPC 4.9 InitialE S /N Initial E S /N 0 TPC E S /N 0 6dB InitialE S /N 0 0dB 10dB TPC 4.9 MCS1 InitialE S /N 0 45dB 50dB MCS3 TPC 4.9 InitialE S /N 0 15dB 30dB AMC MCS MCS 78

86 4 ] s 8 p b M [ 6 t u p h g u 4 ro T 2 0 MCS1 MCS2 MCS3 Proposed E / N S 0 [ db ] Transmitted Power Change [ db ] Initial E S / N0 0dB 10dB 15dB 30dB 45dB 50dB 0dB 10dB 15dB 30dB 45dB 50dB 0 5e-05 10e-05 15e-05 Time [ sec ] 4.9: TPC AMC : (AMC) SIR SIR CRC MCS MCS VSF-OFCDM MCS (TPC) MCS AMC CRC AMC TPC MCS MCS CRC 3G ( ) 3GPP-LTE (Sounding Reference Signal) AMC a 79

87 4 4.7 [4.1] S. Falahati, A. Svensson, T. Ekman, and M. Sternad, Adaptive Modulation Systems for Predicted Wireless Channels, IEEE Trans. on Commun., Vol.52, No.2, pp , February [4.2] V. K. N. Lau and S. V. Maric, Variable Rate Adaptive Modulation for DS-CDMA, IEEE Trans. on Commun, Vol.47, No.4, pp , April [4.3] E. Armanious, D. D. Falconer, and H. Yanikomeroglu, Adaptive Modulation, Adaptive Coding, and Power Control for Fixed Cellular Broadband Wireless Systems: Some New Insight, IEEE WCNC2003, Vol.1, pp , March [4.4] N. Miki, H. Atarashi, S. Abeta, and M. Sawahashi, Comparison of Hybrid ARQ Packet Combining Algorithm in High Speed Downlink Packet Access in a Multipath Fading Channel, IEICE Trans. Fundamentals, Vol.E85-A, No.7, pp , July [4.5] N.Miki, H.Atarashi, S.Abeta, and M.Sawahashi, Comparison of Hybrid ARQ Schemes and Optimization of Key Parameters for High-Speed Packe Transmission in W-CDMA Forward Link, IEICE Trans. Fundamentals, Vol.E84-A, No.7, pp , July [4.6] T. Asai, K. Higuchi, and M. Sawahashi, Experimental Evaluations on Throughput Performance of Adaptive Modulation and Channel Coding and Hybrid ARQ in HSDPA, IEICE Trans. Fundamentals, Vol.E86-A, No.7, pp , July [4.7] M. Dottling, J. Michel, and B. Raaf, Hybrid ARQ and adaptive modulation and coding schemes for high speed downlink packet access, PIMRC 2002, Vol.3, pp , Sept [4.8] K. Tsukakoshi, T. Kobashi, and Y. Kamio, Performance of DS-CDMA Adaptive Modulation System in a Multipath-Channel Environment, IEICE Trans. Commun., Vol.E86-B, No.2, pp , February [4.9] J. Lee, R. Arnott, K. Hamabe, and N. Takano, ADAPTIVE MODULATION SWITCHING LEVEL CONTROL IN HIGH SPEED DOWNLINK PACKET AC- CESS TRANSMISSION, IEE 3G Mobile Communication Technology Conference, May [4.10] A. Harada, S. Abeta, and M. Sawahashi, Adaptive Radio Parameter Control Considering QoS for Forward Link OFCDM Wireless Access, IEEE VTC2002, Vol.3, pp , May [4.11],,,,, IEICE ( ), SST , pp.1-6. [4.12] H. Atarashi, S. Abeta and M. Sawahashi, Variable Spreading Factor-Orthogonal Frequency and Code Division Multiplexing (VSF-OFCDM) for Broadband Wireless Packet Access, IEICE Trans. Commun. Vol.E86-B, No.1, pp , January