Alamouti Code

This paper presents performance analysis of Multiple-Input Multiple- Output - Orthogonal Frequency Division Multiplexing Access (MIMO-OFDMA) wireless system using orthogonal space time block code (OSTBC) over Rayleigh fading channel. OSTBC is an efficient code system that achieves the maximum of diversity gain in mobile communication systems and it is very useful in reducing the processing complexity of the wireless communication system. Several MIMO-OFDMA OSTBC models based on different number of antenna constellation (2Tx,2Rx) and ( 4Tx,2Rx) have been analyzed. The relationship between Bit Error Rate (BER) and Signal to Noise Ratio (SNR) in Rayleigh fading wireless channel has been studied .The simulation results show the effectiveness and accuracy of the MIMO-OFDMA OSTBC system by decreasing BER for low value of SNR compared with the MIMO-OFDMA system. .

Spatial Modulation (SM) provides a multiplexing gain with respect to single-antenna systems by avoiding inter-channel interference. The aim of this paper is to design multiple-antenna wireless systems that exploit the SM concept and analyse e a SM-OSTBC (Orthogonal Space-Time Block Codes) and Alamouti STBC technology. By using analysis and simulation, we would compare the result.

Aeronautical Telemetry links were comprised of a transmit antenna mounted on the underside of fuselage and a fixed ground station equipped with a tracking antenna. Air-toground channel for this telemetry link can be estimated as line of sight propagation. But there is link loss observed at ground control station for certain instant of time. Possible causes of link loss in this case are due to aircraft maneuvering and fading. So analysis of various fade mitigation techniques as well as bit error rate (BER) and signal to noise (SNR) ratio performance comparison between selection diversity, equal gain combining and maximal ratio combining scheme is done. Finally bit error rate performance comparison curve between maximal ratio scheme (MRC) and Alamouti dual antenna transmission scheme is plotted, in order to find out the best scheme for fade mitigation, among all the above mentioned schemes.

Aeronautical Telemetry links were comprised of a transmit antenna mounted on the underside of fuselage and a fixed ground station equipped with a tracking antenna. Air-toground channel for this telemetry link can be estimated as line of sight propagation. But there is link loss observed at ground control station for certain instant of time. Possible causes of link loss in this case are due to aircraft maneuvering and fading. So analysis of various fade mitigation techniques as well as bit error rate (BER) and signal to noise (SNR) ratio performance comparison between selection diversity, equal gain combining and maximal ratio combining scheme is done. Finally bit error rate performance comparison curve between maximal ratio scheme (MRC) and Alamouti dual antenna transmission scheme is plotted, in order to find out the best scheme for fade mitigation, among all the above mentioned schemes.

Bit Error Rate (BER) performance is the most important metric of any digital communication system. MIMO-OFDM systems designed with Alamouti Coding technique, using Error Control Coding schemes has been investigated under this study to achieve BER enhancement and scrutinized for Additive White Gaussian Noise (AWGN) Channel with Inphase and Quadrature-phase (IQ) impairments. This paper details out the model developed using NI LabVIEW and discusses simulation results comparing the error control coding RS, RS-CC and Convolution encoding with 4-PSK and 4-QAM.

We consider a bidirectional relay system using a physical-layer network coding (PNC) protocol with Alamouti's space-time block coding (STBC) at the two source nodes while there is only one antenna at the relay node. Upper and lower bounds on symbol error probability (SEP) are derived for Binary Phase Shift Keying (BPSK) modulation scheme. It is shown that a diversity order of 2 can be achieved even that the relay node has only a single antenna. Simulation results are provided to confirm our analysis for the SEP.

Chaos phenomenon is capable of generating chaotic sequences with low cross-correlation, which can be useful for spreading the direct sequence code division multiple access (DSCDMA) system. In this paper, a chaotic multiple access communication system based on Orthogonal Chaotic Vector (OCV) generated from Rössler system has been proposed. The simulation results showed that the performance of the proposed system is almost the same regardless of the number of users in Additive White Gaussian noise AWGN channel. The results also showed that at bit-error-rate of 10-3, the proposed system has achieved a gain of 6 dB in signal-to-noise ratio over traditional DS-CDMA based on Walsh-Hadamard sequence for single user case in both AWGN and Rayleigh fading channels.

In this paper, the impact of Forward Error Correction (FEC) code namely Trellis code with interleaver on the performance of wavelet based MC-CDMA wireless communication system with the implementation of Alamouti antenna diversity scheme has been investigated in terms of Bit Error Rate (BER) as a function of Signal-to-Noise Ratio (SNR) per bit. Simulation of the system under proposed study has been done in M-ary modulation schemes (MPSK, MQAM and DPSK) over AWGN and Rayleigh fading channel incorporating Walsh Hadamard code as orthogonal spreading code to discriminate the message signal for individual user. It is observed via computer simulation that the performance of the interleaved coded based proposed system outperforms than that of the uncoded system in all modulation schemes over Rayleigh fading channel.

This paper deals with the comparative performance analysis of transmission technique (SISO AND MIMO) and shows the effect on transmission of image. We used four techniques for this category; SISO with Canny edge detection, MIMO with Canny edge detection, SISO without Canny edge detection and MIMO without canny edge detection. The results for each technique are compared with one another so as to choose the best result. These techniques applied on one image for calculating the parameters such as PSNR, MAE, and RMSE. In this paper an attempt is made to study the performance of most commonly used transmission techniques for image transmission and also the comparison on basis of these techniques is carried out by using MATLAB software.

In this paper, the impact of Forward Error Correction (FEC) code namely Trellis code with interleaver on the performance of wavelet based MC-CDMA wireless communication system with the implementation of Alamouti antenna diversity scheme has been investigated in terms of Bit Error Rate (BER) as a function of Signal-to-Noise Ratio (SNR) per bit. Simulation of the system under proposed study has been done in M-ary modulation schemes (MPSK, MQAM and DPSK) over AWGN and Rayleigh fading channel incorporating Walsh Hadamard code as orthogonal spreading code to discriminate the message signal for individual user. It is observed via computer simulation that the performance of the interleaved coded based proposed system outperforms than that of the uncoded system in all modulation schemes over Rayleigh fading channel.

In this paper, the impact of Forward Error Correction (FEC) code namely Trellis code with interleaver on the performance of wavelet based MC-CDMA wireless communication system with the implementation of Alamouti antenna diversity scheme has been investigated in terms of Bit Error Rate (BER) as a function of Signal-to-Noise Ratio (SNR) per bit. Simulation of the system under proposed study has been done in M-ary modulation schemes (MPSK, MQAM and DPSK) over AWGN and Rayleigh fading channel incorporating Walsh Hadamard code as orthogonal spreading code to discriminate the message signal for individual user. It is observed via computer simulation that the performance of the interleaved coded based proposed system outperforms than that of the uncoded system in all modulation schemes over Rayleigh fading channel.

In this paper, the impact of Forward Error Correction (FEC) code namely Trellis code with interleaver on the performance of wavelet based MC-CDMA wireless communication system with the implementation of Alamouti antenna diversity scheme has been investigated in terms of Bit Error Rate (BER) as a function of Signal-to-Noise Ratio (SNR) per bit. Simulation of the system under proposed study has been done in M-ary modulation schemes (MPSK, MQAM and DPSK) over AWGN and Rayleigh fading channel incorporating Walsh Hadamard code as orthogonal spreading code to discriminate the message signal for individual user. It is observed via computer simulation that the performance of the interleaved coded based proposed system outperforms than that of the uncoded system in all modulation schemes over Rayleigh fading channel.

Wireless designers constantly seek to improve the spectrum efficiency/capacity, coverage of wireless networks and link reliability. In this direction, Space-time wireless technology that uses multiple antennas along with appropriate signaling and receiver techniques that offers a powerful tool for improving the wireless performance is used in this thesis work. A special version of STBC called 'Alamouti code' is used. PSK modulation scheme is used for modulation of data. In this thesis work, the Space-Time Block Codes (STBC) is used in WLAN wireless network that uses multiple numbers of antennas at both transmitter and receiver. The STBC which includes the Alamouti Scheme for 2 transmit antenna and a different number of receiving antenna has been studied, simulated and analyzed. The simulation has been done in MATLAB. Throughput and several parameter performance has been analyzed using the MATLAB.A sample image is transmitted to compare the performance of various parameters like RMSE, PSNR, MAE etc. All the parameters are plotted against SNR (in dB) values ranging from-18 to 30. Various observations being made for the improvement in various parameters with increasing SNR and/or with changing diversity scheme. AWGN channel is used here for communication of sampled image data.