Optimal Cooperative Data Transmission Over SC-Fdma on Lte-A Based Networks (original) (raw)

BER Evaluation in LTE SC-FDMA under Multipath Channels

International Journal of Recent Technology and Engineering (IJRTE), 2019

Channel equalization is very essential step in Single Carrier Frequency Division Multiple Access (SC-FDMA) transmission for overcoming the inter-symbol interference (ISI). Also, to evaluate the data-link and network scheduling of LTE technique, a particular channel modelling is crucial. Due to the techniques’ complexity and requirement of high bandwidth for data transmission in literature, we motivated to perform a comparative analysis for BER reduction in SCFDMA scheme with and without equalizer. Therefor, in order to enhance efficiency of performance and functionality of network application, due to huge demand for lower delay, latency and higher speed by the modern users, BER reduction is a significant factor for enhancing signal quality. The substantial focus of this research is to improve the uplink signal of LTE technology by using two type of linear equalization methods such as zero forcing (ZF) and minimum mean square error (MMSE) at receiver part. Moreover, analysis of BER a...

Beamforming for SC-FDMA transmission over MIMO ISI channels with decision-feedback equalization

2010 International ITG Workshop on Smart Antennas (WSA), 2010

We consider transmit beamforming algorithms for single-carrier frequency-division multiple access (SC-FDMA) transmission over frequency-selective multiple-input multipleoutput (MIMO) channels. The beamforming filters are designed for optimum performance of MIMO minimum mean-squared error decision-feedback equalization (MMSE-DFE). It turns out that eigenbeamforming diagonalizing the overall channel is optimum, and in addition an optimum power allocation has to be performed which is similar in spirit to classical results for the optimum continuous-time transmit filter for linear modulation formats obtained by Yang and Roy. Simulation results indicate that the proposed solution is beneficial for the block error rate performance of an SC-FDMA transmission scheme with strong channel coding and error-free decisions in the feedback path of MMSE-DFE, which can be guaranteed e.g. by equivalent Tomlinson-Harashima precoding at the transmitter side.

Optimized OFDM Model Using CMA Channel Equalization for BER Evaluation

Orthogonal Frequency Division Multiplexing (OFDM) is a type of Multicarrier Modulation (MCM) technique in which entire bandwidth is divided into large number of small sub-carriers and each subcarrier is transmitted parallel to achieve higher data rates. It has various applications like Digital Audio Broadcasting (DAB), Digital Video Broadcasting (DVB) and wireless LAN.OFDM technique is widely used in wireless communication system because of its very high data rate. The performance of FFT based OFDM system using Linear and cyclic channel coding and Constant Modulus Algorithm (CMA) equalizer is simulated using simulink model. The BER saving using the optimized proposed model with both linear and cyclic channel coding along with CMA equalizer is evaluated. The proposed work using cyclic channel coding with QPSK/QAM modulation and CMA as channel equalization under AWGN channel results in 52.6% and 96.3% BER reduction as compared to conventional OFDM model without channel coding, channel equalization and channel fading. So, CMA equalizer is used to enhance the performance of OFDM system. Keywords: Multicarrier Modulation (MCM), Constant Modulus Algorithm (CMA), Digital Video Broadcasting (DVB), Digital Audio Broadcasting (DAB), subcarrier 1. Introduction OFDM is an attractive modulation scheme with strongly efficient in bandwidth usage, immunity against multipath fading environment. It has less Inter Channel Interference (ICI), Inter Symbol Interference (ISI) and provides better spectral efficiency. OFDM has various merits over the conventional digital modulation techniques however, there are certain limitations of OFDM such as high Peak to Average Power Ratio (PAPR), high Bit Error Ratio (BER) and synchronization problem. In a wireless communication channel, the transmitted signal can travel from transmitter to receiver over multiple reflective paths. This gives rise to multipath fading which causes fluctuations in amplitude, phase and angle of arrival of the received signal. For example, the transmitted signal from the BTS (base transceiver station) may suffer multiple reflections from the buildings nearby, before reaching the mobile station. Such multipath fading channels are often classified into slow fading/fast fading and frequency-selective/flat fading channels. The performance of OFDM has been further enhanced by using various equalization techniques.

Performance Evaluation of ZF & MMSE Channel Equalization techniques in LTE downlink .docx

kabaka, 2016

In this paper we will introduce a comprehensive study based on LTE techniques that are used in order to eliminate or reduce different types of interferences that happens in the wireless communication channel and affect the received signal at receivers which associated with channel equalization techniques by comparing between three different techniques which are the Zero Forcing ZF, the Minimum Mean Square Error MMSE and the Soft Sphere Decoding SSD. Also different types of modulations are considered such as QPSK, 16QAM, and 64QAM. The comparison is performed for different transmission modes such as SISO, SIMO, and MIMO. And the results show that for SISO and MIMO the MMSE has the advantage over the ZF equalizer, and in SIMO the ZF is performing better than the MMSE, and finally for the MIMO we figure that the SSD equalizer has advantage over both other equalizers.

Investigation of LTE Receivers in Term of Channel Equalization Techniques in LTE Downlink

International Journal of Science and Research (IJSR), 2016

In this paper we will introduce a comprehensive study based on LTE techniques that are used in order to eliminate or reduce different types of interferences that happens in the wireless communication channel and affect the received signal at receivers which associated with channel equalization techniques by comparing between three different techniques which are the Zero Forcing ZF, the Minimum Mean Square Error MMSE and the Soft Sphere Decoding SSD. Also different types of modulations are considered such as QPSK, 16QAM, and 64QAM. The comparison is performed for different transmission modes such as SISO, SIMO, and MIMO. And the results show that for SISO and MIMO the MMSE has the advantage over the ZF equalizer, and in SIMO the ZF is performing better than the MMSE, and finally for the MIMO we figure that the SSD equalizer has advantage over both other equalizers.

Analysis the Performance of OFDM-MIMO Channel with Different Equalizers

Journal of Network and Information Security, 2022

The excellent efficiency, capacity, and dependability of today's wireless networks are concurrent to be achieved, and employing several communication methods antennas is an effective solution that has been extensively used. A communication system where both terminals are equipped with multi-antennas are referred to as MIMO systems, and when combined with OFDM technology are referred to as MIMO-OFDM. MIMO-OFDM has the ability to serve a large number of users with an enormous data transmission speed communication as well as utilizing the bandwidth efficiently. The aim of this simulation task explores three different equalization schemes in the MIMO flat fading channel, frequency-selective OFDM channel, and combined OFDM-MIMO wireless links on the bit error rate (BER) metric. Throughout the simulations, we modulate in 4-QAM (MIMO, OFDM-MIMO) and 16-QAM (OFDM) and observe BER performances for signal-to-noise ratio (SNR) up to 30. We find that given the specifications for OFDM as defined in IEEE 802.11a, precoding, and zeroforcing schemes in MIMO yield similar BER performances, while the MMSE scheme performs slightly worse at higher SNR's. Based on the equalization scheme, we assume perfect channel state information at the transmitter (CSIT) (for precoding) and the receiver (CSIR) (for zero-forcing and MMSE).

Inter Carrier Interference Analysis of SCFDMA System using Frequency Domain Equalization

Procedia Technology, 2012

Single Carrier Frequency Division Multiple Access (SCFDMA) system performs better than multicarrier transmission systems due to its inherent single carrier structure. It is a strong candidate for uplink communication due to its lower peak to average power ratio (PAPR) but it is high sensitive to carrier frequency offset. However the problem of intercarrier interference (ICI) in SCFDMA system is not addressed. In this paper conjugate cancellation method is used to reduce the effect of frequency offset in SCFDMA system. Bit error rate of OFDMA and SCFDMA system is compared in different multipath channels using zero forcing equalizer (ZFE) and Minimum mean square error (MMSE) equalizers. Simulation results shows that ZFE performs better for additive white gaussian noise (AWGN) and pedestrian channels but its performance gets degraded in vehicular channels. MMSE equalizer performs better than zero forcing equalizer up to 0.2 normalized frequency offset in vehicular channels.

Comparison of SC-FDE and OFDM Modulation Schemes for 4G Wireless Communication Systems

In this paper, we have investigated the LTE-A uplink (User Equipment to eNodeB), and performed link level analysis and simulation of Single-Carrier Frequency Domain Equalization (SC-FDE) in comparison to Orthogonal Frequency Division Multiplexing (OFDM). The comparison has been done in terms of Signal to Noise Ratio (SNR), Symbol Error Rate (SER) using Zero-Forcing (ZF) and Minimum Mean Square Error (MMSE) equalization techniques, and the results show that the performances of the two techniques are similar for a frequency flat fading channel and that the use of appropriate cyclic prefix of length not less than the Doppler spread of the channel improves performance of both systems.