P. Sindhu, D. B. Sasanka, Kakarla Hari Kishore · International Journal of Computer Applications · 2013
MIMO systems with multiple antenna elements at both Transmitter and Receiver ends are an efficient solution for future wireless communication systems. They provide high data rates by exploiting the spatial domain under the constraints of limited bandwidth and transmit power. Space-Time Block Coding is a MIMO transmit strategy which exploits transmit diversity and high reliability. In the present paper performance analysis and a comparative study is reported for Alamouti code using transmit-receive diversity ( 2x1, 2X2, 2x3) with maximum likelihood detection technique. The channel is assumed to be flat Rayleigh fading channel and noise samples are independent with zero mean complex Gaussian random variable. The Alamouti Space Time Block codes with modulation techniques BPSK, QPSK and 16-QAM are used to obtain the bit error rate performance under different SNR scenarios. The results reported in this paper suggest substantial improvement in the system performance by incorporating multiple input multiple output techniques in order to improve the link quality.
Cited by 2Open access
Shahid Mumtaz, Ghaya Rekaya-Ben Othman, Yves Jaouën et al. · 2011
We theoretically and experimentally investigate the performance of the Alamouti polarization-time code to mitigate PDL. We show that due to the orthogonal structure of its codewords, it can entirely compensate PDL.
Cited by 8
R. Vishwanath, Manav R. Bhatnagar · Wireless Personal Communications · 2006
Cited by 9
Huixu Luan, Miao Lv, Jihong Wang et al. · IEEE Internet of Things Journal · 2025
Backscatter communications, an emerging low-cost and low-consumption green communication paradigm, has received significant attention in both industry and academia. In recent years, multiple-input multiple-output (MIMO) technology has also been integrated into backscatter communications to meet the requirements of transmission performance in IoT scenarios. However, due to the hardware limitations of backscatter tags, one of the main challenges for multi-antenna backscatter tags is to reduce the circuit complexity of space-time block codes (STBC) while maintaining transmission performance. Although low-complexity STBC for dual-antenna tags has been explored, to the best of our knowledge, research on high-performance, low-complexity STBC for four-antenna tags remains in its infancy. In this paper, we propose a 2×4 extended Alamouti code (EAC) with full-rate capability for MIMO backscatter communications. The results show that the required impedance of the proposed EAC on the backscatter tag is less than half of that of the conventional orthogonal STBC (OSTBC), which considerably reduces the complexity of the tag circuit. Additionally, we also derive the asymptotic closed form expression of the symbol error rate (SER) of the proposed EAC to obtain the system insights. The derivation results show that the achievable diversity order of the proposed EAC in 1×4×N backscatter channel is 2×min(2,N), which indicates that the proposed EAC can achieve the same diversity performance as the conventional OSTBC by setting an appropriate number of receiver antennas. Finally, numerical simulations are performed to validate the accuracy of our analysis and the superiority of the proposed EAC in SER.
Cited by 0
Biljana Badic, Hans Weinrichter · 2003
Abstract — Since the publication of Alamouti’s famous (2 × 2) space-time block code, various suboptimal space-time codes for multi-input/multi-output fading channels for four transmit antennas have been proposed not achieving full diversity at full rate. In this paper we present a simple adaptive, channel dependent, rate-one Extended Alamouti space-time block code for four transmit antennas and one receive antenna using partial feedback. The relevant channel state information is sent back from the receiver to the transmitter quantized to one or two bits per code block. In this way signal transmission with improved diversity is achieved being near to the maximum diversity value of d = 4. Such high diversity can be exploited with zero forcing receiver as well as with maximum-likelihood (ML) receiver. I.
Cited by 0
Rajab M. Legnain, Roshdy H. M. Hafez · 2011
This paper presents a new scheme for demodulate-and-forward two-way relaying scheme based on Alamouti code. Two nodes, A and B, employ Space-Time Alamouti code to transmit their messages to each other through relay node (RN). The RN receiver uses Minimum Mean Square Error Successive Interference Cancellation (MMSE-SIC) to separate signals originating at nodes A and B. The RN transmitter applies XOR to combine the two received demodulated signals, the composite signal is modulated and broadcasted using Alamouti Code. The proposed scheme does not require Channel State Information (CSI) at the transmitters of A, B and RN. Furthermore, If the number of antennas at each of nodes A and B is two, then RN requires two antennas to separate the two signals. As the number of antenna increases at relay node, the performance of the system improves significantly.
Cited by 7
Mayank Gupta, Govind Murmu · 2018
In wireless communication system, transmitted signal is received at the receiver from various paths. This happens because of scattering object which are present in the Line of Sight (LOS) path in wireless communication channel. Due to this multipath reception of the signal at the receiver, there occurs constructive or destructive interference which gives rise to fading. In this paper, the problem of fading in the multipath system is studied using simple models for multipath propagation. Extensive SIMULINK <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">®</sup> models are presented to show the cases where a transmitted signal is traveling through multipath trajectories and reaches at receiver. A Rayleigh fading channel is modelled to show this multipath effect. A comparison is made between the performance of AWGN channel and Rayleigh fading channel keeping Bit Error Rate (BER) as a parameter. It is also observed that by using more number of receivers, the BER of the fading channel can be brought closer to the ideal situation. Further, it is shown that effective use of Alamouti Space-Time Block code improves BER significantly in MIMO system considering multiple receivers in comparison with Rayleigh fading channel.
Cited by 4
Michael J. Turpin · 2004
Cited by 0
Saman Atapattu, Nandana Rajatheva · 2008
In this paper, we examine a general time-division multiple-access (TDMA) cooperative protocol. The wireless network consists of a source terminal, a destination terminal and n - number of intermediate relay terminals that operate in amplify-and-forward (AF) mode with a fixed-gain. Starting with the moment generating function (MGF) of the end-to-end output signal-to-noise ratio (SNR), the symbol error rate (SER) performance of M-ary phase shift keying (M-PSK) modulation schemes is theoretically investigated over independent and identical (i.i.d) Nakagami-m fading environments with maximal ratio combining (MRC) scheme at the destination. Subsequently, numerical and simulation results are provided to verify the accuracy of the formulation.
Cited by 11
Esa R. Alotaibi, Daniel K. C. So, Khairi Ashour Hamdi · 2015
The cooperative diversity technique, combined with distributed space-time coding (DSTC), can efficiently improve the secrecy capacity and transmission reliability of wireless communication systems. In this paper, a multicast cooperative relaying system, based on distributed Alamouti space-time coding, is proposed, as a method of preventing an eavesdropper from accessing source data. A maximum likelihood (ML) decoder at the destination was chosen to receive the data, however, the ML decoder was unable to receive data at the eavesdropper. An analysis was carried out to synchronize DSTC, a Rayleigh fading channel, a Rician fading channel, and a combination thereof. It was assumed that channel state information (CSI) for the relay-destination link was known, although this was unknown for the relay-eavesdropper link. The theoretical results for the secrecy outage probability for the proposed scheme are then compared with existing results.
Cited by 1
Fahd Ahmed Khan, Yunfei Chen, Mohamed‐Slim Alouini · 2011
Coherent receivers are derived for a pilot-symbol aided distributed Alamouti-coded system with imperfect channel state information. The derived coherent receivers do not perform channel estimation but rather use the received pilot signals for decoding. The derived receiver metrics use the statistics of the channel to give improved performance. The performance is further improved by using the decision history. Simulation results show that a performance gain of up to 1.8 dB can be achieved for the new receivers with decision history as compared with the conventional mismatched coherent receiver.
Cited by 3
Dejin Kong, X. Zheng, Yukang Tian et al. · Digital Communications and Networks · 2021
In this paper, we address the Alamouti code in Filter-Bank Multicarrier with Offset Quadrature Amplitude Modulation (FBMC/OQAM) and propose a novel block-wise Alamouti code, in which a repeated block is designed to eliminate the imaginary interference among FBMC/OQAM symbols. The proposed approach exhibits a higher spectral efficiency than the conventional block-wise Alamouti scheme, as only one column of zero symbols is used as a guard interval instead of two. Furthermore, compared to the conventional scheme, the bit error ratio is improved in the proposed block-wise Alamouti, as the assumption on channel invariance at two adjacent subcarriers is not required. Simulation results indicate that, with a significantly reduced overhead, the proposed Alamouti scheme achieves better performance over the conventional block-wise Alamouti scheme.
Cited by 6Open access
Safwat M. Ramzy · Menoufia Journal of Electronic Engineering Research · 2020
Abstract In this paper, we introduced another methodology for the cooperative network using the maximum posterior (MAP) and the Alamouti code decoding scheme for the multiple-input single-output (MISO) wireless networks that use decode and forward (DF) protocol as a cooperation protocol. Without loss of generality, the considered network consists of one source, one relay and one receiver. A closed-form expression for the upper bound of the bit error probability is derived. The obtained upper bound expression can be utilized in the power optimization problems, relay positioning issue. The results that are shown in this paper clear that the proposed scheme has two advantages over the related work. The first advantage is that it has less complexity. The second one is that it has better spectrum efficiency by using less number of channels. Therefore, our contribution can be summarized in improving the spectrum efficiency and reducing the complexity of the cooperative network, but the paid price is that the bit error rate increases by a little ratio.
Cited by 0Open access
Biljana Badic, Markus Rupp, H. Weinrichter · ETRI Journal · 2004
Since the publication of Alamouti's famous space-time block code, various quasi-orthogonal space-time block codes (QSTBC) for multi-input multi-output (MIMO) fading channels for more than two transmit antennas have been proposed. It has been shown that these codes cannot achieve full diversity at full rate. In this paper, we present a simple feedback scheme for rich scattering (flat Rayleigh fading) MIMO channels that improves the coding gain and diversity of a QSTBC for 2n (n = 3, 4,…) transmit antennas. The relevant channel state information is sent back from the receiver to the transmitter quantized to one or two bits per code block. In this way, signal transmission with an improved coding gain and diversity near to the maximum diversity order is achieved. Such high diversity can be exploited with either a maximum-likelihood receiver or low-complexity zero-forcing receiver.
Cited by 22Open access
Safwat M. Ramzy · Menoufia Journal of Electronic Engineering Research · 2021
In this paper, we introduced another methodology for the cooperative network using the maximum posterior (MAP) and the Alamouti code decoding scheme for the multiple-input single-output (MISO) wireless networks that use decode and forward (DF) protocol as a cooperation protocol. Without loss of generality, the considered network consists of one source, one relay and one receiver. A closed-form expression for the upper bound of the bit error probability is derived. The obtained upper bound expression can be utilized in the power optimization problems, relay positioning issue. The results that are shown in this paper clear that the proposed scheme has two advantages over the related work. The first advantage is that it has less complexity. The second one is that it has better spectrum efficiency by using less number of channels. Therefore, our contribution can be summarized in improving the spectrum efficiency and reducing the complexity of the cooperative network, but the paid price is that the bit error rate increases by a little ratio
Cited by 0Open access
İbrahim Aydın, Ümit Aygölü · Wireless Networks · 2014
Cited by 3
İbrahim Aydın · Istanbul Technical University Academic Open Archive (Istanbul Technical University) · 2010
Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2010
Cited by 0Open access
2015
Abstract:- Alamouti space-time code for two transmit antennas is most attractive due to simplicity of its encoding and decoding algorithms. However, it does not provide any coding gain. This paper proposes a new space-repetition code for two transmit antennas and one receive antenna based on one bit feedback. This can provide a relatively significant coding gain while it’s encoding and decoding complexity is less than Alamouti code. Although the orthogonal design theory does not satisfy, the new code achieves maximum transmit diversity. Even if the reverse channel is not reliable, the performance of the new code still remains better than that of the Alamouti code. All the above advantages are achieved while preserving spectral efficiency with respect to Alamouti code. The only price paid for these advantages is one bit feedback from the receiver to the transmitter which can be easily returned with the ACK signal to the transmitter. Energy computations are also presented and it is shown that the new code can save energy compared to Alamouti code. Key-Words:- MIMO channels, space-time coding, antenna diversity, multipath propagation, channel modeling, channel estimation. 1
Cited by 0
Miguel Bazdresch, Mohammed G. Al-Hamiri · 2017
A digital communications receiver requires precise symbol synchronization before the transmitted information can be recovered. Gardner's algorithm is a synchronizer that can acquire and track timing with only two samples per symbol, and it does not require prior carrier synchronization. In this paper, a feed-forward, all-digital version of Gardner's algorithm is presented. It is shown that this synchronizer is effective when used in a wireless Alamouti space-time coded system. Besides retaining its immunity to carrier frequency offset, the algorithm does not require knowledge of the channel gains. Simulation results are presented along with mean-square estimates of the timing error for different values of signal to noise ratio and for staggered and non-staggered pulses.
Cited by 5
Guozhen Zang, Baohua Huang, Jing Mu · 2010
Aiming at the low Earth orbiting (LEO) satellite mobile communication, the cooperative diversity technology is applied to the forward downlink in this paper, and one scheme for cooperative diversity with two satellites based on the Alamouti code is presented. To reduce the non-negligible path delay from the different satellite to the same terminal, the synchronous CDMA is used and satellites are distinguished by the spreading codes which are orthogonal each other in this scheme. Simulation results show the satellite cooperative diversity system can obtain better performance than the traditional uncoded BPSK system with the same fading channel and system parameters. Though the satellite cooperative diversity system has worse performance than the traditional satellite diversity system, it has the advantage in communication range and low complex mobile terminal. Particularly, this new scheme can be used as an effective means to improve the performance in the area where the gateway can not be built.
Cited by 6