In this paper, we consider two coded SFBC-OFDM systems for four transmit and two receive antennas in broadband wireless channels. Using a linear simplified ZF receiver and a reduced complexity APP detector, we compare QO-SFBC and hybrid SM-SFBC in time varying multipath fading channels. We examine the results in terms of bit-error-rate and capacity for different channel characteristics. We show...

–One of the biggest drawbacks of OFDM is its high peak to average power ratio (PAPR). High PAPR of OFDM makes it unusable in non-linear systems. So the clipping signals scheme is one useful and simple method to reduce the PAR. This paper presents a new receive algorithm called MIMO CI-OFDM has been implemented. From the simulation results, it is shown that MIMO SFBC CI-OFDM reduces PAPR signifi...

Time variation within an OFDM symbol causes intercarrier interference (ICI). In this letter, frequency-domain partial response coding (PRC) is investigated to reduce ICI in the Alamouti SFBC-OFDM system. Based on the expression of the ICI power in the SFBC-OFDM system with PRC, the near-optimal weights of PRC are derived. Simulation results show that the PRC scheme can reduce ICI effectively. k...

Space frequency block code orthogonal frequency division multiplexing (SFBC-OFDM) systems has inherit drawbacks of high peak-to average power ratio (PAPR) signals, and constellation shaping with trellis is a promising approach for reducing both peak power and bit error rate of SFBC-OFDM signals. In practice, reliability will improve in SFBC-OFDM by employing coded modulation. In this work, it h...

Single-carrier space frequency block coding (SC-SFBC) is an innovative mapping scheme suitable for implementing transmit diversity in single-carrier frequency division multiple access (SC-FDMA) systems. The main advantage of SC-SFBC is that it preserves the low envelope variations of SC-FDMA, which is particularly interesting for the uplink of wireless communications systems. In this article, w...

Space-frequency block coded transmit diversity (SFBC) is under intensive study to improve the transmission performance of multi-carrier transmission in a frequencyselective fading channel. However, in the conventional SFBC, the transmission efficiency degrades when more than 3 transmit antennas are used. Recently, we proposed a spacetime block coded-joint transmit/receive antenna diversity (STB...

This paper presents a highly robust space-frequency block coded (SFBC) multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) system. The proposed system is based on applying a short block length Walsh Hadamard transform (WHT) after the SFBC encoder. The main advantage of the proposed system is that the channel frequency responses over every two adjacent subcarr...

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 filterin...

In a high mobility environment, single-carrier (SC) space-frequency block coding (STBC) diversity achieves better bit error rate (BER) performance than SC space-time block coding (STBC) diversity. However, in a strong frequency-selective fading channel, the BER performance degrades due to the orthogonality distortion of SFBC codeword. In this paper, we propose a frequency-domain equalization (c...

The multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) system with space-frequency block coding (SFBC) is an attractive technique due to its robustness for time selective fading channels. SFBC MIMO-OFDM systems have a high computational complexity since the number of inverse fast Fourier transforms (IFFTs) required scales in direct proportion to the number o...