Cyclic delay diversity based space-time/space-frequency coded MC-CDMA system

2006 ◽  
Vol 1 (3) ◽  
pp. 22-29 ◽  
Author(s):  
Afzal Lodhi ◽  
Fatim Said ◽  
A. Aghvami
Keyword(s):  
Space Time ◽  
Cdma System ◽  
Cyclic Delay Diversity ◽  
Time Space ◽  
Space Frequency ◽  
Delay Diversity

Adaptive Spatial Mode Of Space–Time And Spacefrequency OFDM System Over Fading Channels

2012 ◽  
Author(s):  
Nor K. Noordin ◽  
Borhanuddin M. Ali ◽  
S. S. Jamuar ◽  
Tharek A. Rahman ◽  
Mahamod Ismail
Keyword(s):  
Fading Channels ◽  
Channel Coding ◽  
Orthogonal Frequency Division Multiplexing ◽  
Multipath Fading ◽  
Individual Performance ◽  
Space Time ◽  
Delay Spread ◽  
Spatial Mode ◽  
Time Space ◽  
Space Frequency

Dalam kertas kerja ini kami membentangkan skema mod ruang (ASM) adaptif 2 menghantar 1 menerima (2 Tx : 1 Rx) menggunakan kaedah ruang–masa (ST) dan ruang frekuensi (SF) multiplekskan pembahagian frekuensi ortogonal (OFDM). Pada nilai nisbah isyarat ke hingar yang rendah kami menggunakan ST–OFDM dan menukar kepada mod SF–OFDM pada nilai ambang yang telah ditentukan. Nilai ini ditentukan berdasarkan titik silang antara lengkuk prestasi kedua–dua mod. Keputusan simulasi menunjukkan gandaan banyak 9 dB (pada kadar ralat bit 10–3) diperolehi dengan menggunakan mod ruang adaptif (ASM) berbanding dengan ST–OFDM tanpa kod, lebih kurang 6 dB berbanding SF–OFDM, 4 dB berbanding ST–OFDM terkod dan gandaan sebanyak 2 dB berbanding SF–OFDM terkod, pada rebak lengah 700 ns. Kata kunci: OFDM, ruang–masa, ruang–frekuensi, pengekodan saluran dan saluran pemudaran berbilang laluan In this paper we present a 2 transmit 1 receive (1 Tx : 1 Rx) adaptive spatial mode (ASM) of space–time (ST) and space–frequency (SF) orthogonal frequency division multiplexing (OFDM). At low signal to noise ratio (SNR) we employ ST–OFDM and switch to SF–OFDM at a certain SNR threshold. We determine this threshold from the intersection of individual performance curves. Results show a gain of 9 dB (at a bit error rate of 10–3) is achieved by employing adaptive spatial mode compared to a fixed ST–OFDM, almost 6 dB to fixed SF–OFDM, 4 dB to Coded ST–OFDM and 2 dB to a fixed coded SF–OFDM, at a delay spread of 700 ns. Key words: OFDM, space–time, space–frequency, channel coding and multipath fading channels

On space-frequency coding using cyclic delay diversity for OFDM-based transmission systems

2003 ◽  
Vol 14 (6) ◽  
pp. 491-500
Author(s):  
Axel Huebner ◽  
Frank Schuehlein ◽  
Martin Bossert ◽  
Elena Costa ◽  
Harald Haas
Keyword(s):  
Transmission Systems ◽  
Cyclic Delay Diversity ◽  
Frequency Coding ◽  
Space Frequency ◽  
Delay Diversity
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