h间= F-filtery回,x间 h:[mP+n]=T-fiterhi[mP+n-1], hi[mP+n-2 hmP+n-d r#2,Fd=50 wimP+n'lX, hi[mP +n] f EM Algorithm eac3、Fd20t hi[mP+n]=F.. [m,x(mI end Figure 4: Typical urban(TU) fading channels with Doppler fre- quencies fa= 50Hz and fa=200Hz. Table 1: Procedure for computing X)for the EM algorithm Encode Modulator 二m了 入2 MAP Chan Turbo Iteral, Fd=200Hz 一 Turbo itert5,Fd200Hz In⊥tia1 Sianahtc-Noe。RaB Figure 2: Transm receiver structure for an STBC-OFDM Figure 5: STBC-OFDM systems employing outer convolutional system with outer code. Ii denotes the interleaver and code. Two-ray fading channels with Doppler frequencies fa II- denotes the nding deinterleaver 50Hz and a= 200Hz urbo iter5. Fd=200Hz 一 EM Iter.Fd=200Hz IdeAl CsI Figure 6: STBC-OFDM systems employing outer convolutional Figure 3: Two-ray fading channels with Doppler frequencies fa code. Typical urban(TU) fading channels with Doppler frequen 50Hz and fa= 200Hz cies fa= 50Hz and fa= 200Hzâá ✌✹ãä✵å = F-filter æ ✌ ãä✵å✏ç✦è❶ãä✵å ç é✯ê➄ë➞ç✙ì❆ì✙ì✙ç✞íîç for ï êðä❋ç❻ë➞ç✙ì✙ì✙ì❆ç✞ñóò☛ë for ô ê◆ë➞ç♦õ❋ç❭ì❆ì✙ì❆ç✦ö â÷ ✌✏ãïö●ø ô å = T-filter âá ✌✹ãïö●ø ô ò✪ë✹å✏ç âá ✌✹ãïö●ø ô òùõ✵å✏ç✙ì❆ì✙ì❆ç âá ãïö●ø ô òùú✞å çûéqê➄ë➞ç❭ì❆ì✙ì❆ç❏íîç end è♠ ❞ s ãïå = arg max➎ ✌➏ ✘q✚ ➫ ü ➸ ✘✛✚ ý➺þ✵ÿ✁￾ æ ✌ ãïö●ø ô➲ å èç â÷ ✌✏ãïö❶ø ô➲ å ç ✂☎✄✝✆ è♠④Ó s ãïå = EM æ✌ ãïå ✌ ç❑è♠ ❞ s ãïå ç [cf. EM Algorithm] for ô ê◆ë➞ç♦õ❋ç❭ì❆ì✙ì❆ç✦ö âá ✌✏ãïö●ø ô å = F-filter æ✌ ãïå✏ç✦è♠④Ó s ãïå ç❏éqê➄ë➞ç❭ì❆ì❆ì✙ç❏íîç✞✂☎✄✞✄✝✆ end end Table 1: Procedure for computing ✜ ♠ ❞ s for the EM algorithm. . . . . . . . . . . . . IFFT IFFT Encoder Π Modulator MPSK STBC Encoder FFT FFT Decoder (0) X MAP Channel o (p=0) EM Alg. Initial. Pilot (p=0) o Decoder Channel λ MAP-EM STBC λ1 e e 2 Π Π -1 Figure 2: Transmitter and receiver structure for an STBC-OFDM system with outer channel code. ✟ denotes the interleaver and ✟r ✚ denotes the corresponding deinterleaver. 0 2 4 6 8 10 12 14 16 10−3 10−2 10−1 100 STBC−OFDM in two−path Fading Channels, without CSI OFDM Word Error Rate, WER Signal−to−Noise Ratio (dB) EM Iter#1, Fd= 50Hz EM Iter#2, Fd= 50Hz EM Iter#3, Fd= 50Hz EM Iter#1, Fd=200Hz EM Iter#2, Fd=200Hz EM Iter#3, Fd=200Hz Ideal CSI Figure 3: Two-ray fading channels with Doppler frequencies Ï❡Ð ✔ ß❈ Hz and Ï❡Ð ✔➀➆✙❈✫❈Hz. 0 2 4 6 8 10 12 14 16 10−3 10−2 10−1 100 STBC−OFDM in TU Fading Channels, without CSI OFDM Word Error Rate, WER Signal−to−Noise Ratio (dB) EM Iter#1, Fd= 50Hz EM Iter#2, Fd= 50Hz EM Iter#3, Fd= 50Hz EM Iter#1, Fd=200Hz EM Iter#2, Fd=200Hz EM Iter#3, Fd=200Hz Ideal CSI Figure 4: Typical urban (TU) fading channels with Doppler fre￾quencies Ï✫Ð ✔ ß❈ Hz and Ï✫Ð ✔➀➆✙❈✓❈Hz. 0 1 2 3 4 5 6 10−3 10−2 10−1 100 STBC−OFDM in two−path Fading Channels, without CSI OFDM Word Error Rate, WER Signal−to−Noise Ratio (dB) Turbo Iter#1, Fd= 50Hz Turbo Iter#3, Fd= 50Hz Turbo Iter#5, Fd= 50Hz Turbo Iter#1, Fd=200Hz Turbo Iter#3, Fd=200Hz Turbo Iter#5, Fd=200Hz Ideal CSI Figure 5: STBC-OFDM systems employing outer convolutional code. Two-ray fading channels with Doppler frequencies Ï✫Ð ✔ ß❈ Hz and Ï✫Ð ✔➀➆✙❈✫❈Hz. 0 1 2 3 4 5 6 10−3 10−2 10−1 100 STBC−OFDM in TU Fading Channels, without CSI OFDM Word Error Rate, WER Signal−to−Noise Ratio (dB) Turbo Iter#1, Fd= 50Hz Turbo Iter#3, Fd= 50Hz Turbo Iter#5, Fd= 50Hz Turbo Iter#1, Fd=200Hz Turbo Iter#3, Fd=200Hz Turbo Iter#5, Fd=200Hz Ideal CSI Figure 6: STBC-OFDM systems employing outer convolutional code. Typical urban (TU) fading channels with Doppler frequen￾cies ÏÐ ✔ ß❈ Hz and ÏÐ ✔➀➆✙❈✓❈Hz