Prostorno-frekvencijsko blok kodiranje sa odsjecanjem i filtriranjem kao tehnika predajni diverziti u SC-FDMA

The paper presents Space-Frequency Block Coding (SFBC) as a transmit diversity technique in Single Carrier Frequency Division Multiple Access (SC-FDMA). SC-FDMA is known as a low Peak-to-Average Power Ratio (PAPR) modulation technique. SFBC requires changing the order of the samples in the frequency domain, which results in increase of the PAPR. Because of that, additional clipping and filtering is proposed to be performed after SFBC to preserve low PAPR level and to avoid the out-of-band radiation. This affects the performance, but still provides significant advantage to the existing techniques, as is shown using simulationsOvaj papir predstavlja prostorno-vremensko blok kodiranje (SFBC) kao tehniku predajnog diverzitija u Single Carrier Frequency Division Multiple Access (SC-FDMA) sustavima. SC-FDMA je poznat kao modulacijska tehnika sa niskim omjerom vršne i srednje snage (PAPR). SFBC zahtjeva izmjenu redoslijeda uzoraka u frekvencijskoj domeni, što rezultira povećanjem PAPR-a. Zbog toga, dodatno odsjecanje (clipping) i flitriranje signala nakon SFBC-a je predloženo u cilju očuvanja niske vrijednosti PAPR-a i izbjegavanja zračenja van opsega. Ovo utječe na performance, ali idalje pruža značajnu prednost nad postojećim tehnikama, kao što je pokazano kroz simulacije

Three-Time-Slot Quasi-Orthogonal Space-Time Block Codes

Abstract—In this paper, a class of quasi-orthogonal space-time block codes (Q-STBC) is proposed for systems with 2 antennas and 3 time slots, where the orthogonal Alamouti code can not be applied due to the odd, known also as Orphan, symbol problem inherited in the 3GPP frame structure. The proposed codes can achieve full rate and full diversity with lower complexity maximum likelihood detection. The design also takes into consideration other issues, such as the power fluctuation, the compatibility with single antenna transmission mode, the receiver and transmitter complexity etc. Index Terms — Space time block coding, spatial diversity, fading I