Abstract Cooperative communication is one of the emerging technologies that promise significantly higher reliability and spectral efficiency in wireless networks. It is a new form of diversity that allows users or nodes to share resources to create collaboration via distributed transmission and processing of messages. As candidate multiple access for future radio access, Non orthogonal multiple access (NOMA) over orthogonal multiple access (OMA) are... Cooperative communication is one of the emerging technologies that promise significantly higher reliability and spectral efficiency in wireless networks. It is a new form of diversity that allows users or nodes to share resources to create collaboration via distributed transmission and processing of messages. As candidate multiple access for future radio access, Non orthogonal multiple access (NOMA) over orthogonal multiple access (OMA) are adopted as downlink access scheme for future 5th generation mobile communication. In this paper, we compare user throughput when using orthogonal multiple access (OMA) and NOMA in macro femto network. We show through computer simulation the effect of imperfect interference cancellation on user throughput. We assist the performance of user selection when using fixed power allocation. Finally, we propose NOMA with COMP scenario whose performance improvement lead for user and cell throughput. Read More Read Less

Abstract This paper evaluates the performance of Long Term Evolution (LTE) downlink with multiple inputs and multiple outputs (MIMO) techniques, where the use of multiple antennas at the transmitter and receivers. There are different combinations of array configuration and polarization, transmission and detection schemes that can be implemented to achieve different purposes in functional and performance terms. MIMO transmissions schemes include transmit diversity and spatial... This paper evaluates the performance of Long Term Evolution (LTE) downlink with multiple inputs and multiple outputs (MIMO) techniques, where the use of multiple antennas at the transmitter and receivers. There are different combinations of array configuration and polarization, transmission and detection schemes that can be implemented to achieve different purposes in functional and performance terms. MIMO transmissions schemes include transmit diversity and spatial multiplexing and MIMO detection schemes such as zero forcing and soft spheres decoding (SSD). The performance metrics considered are throughput and bit error rate (BER) and these are used to evaluate the performance of LTE in flat fading and International Telecommunications Union B (ITU-B) Pedestrian channel with zero forcing and soft sphere decoding for Single Input Single Output (SISO), transmit diversity and spatial multiplexing. The simulations show that the performance of MIMO is better than SISO in both channel models particularly when SSD is employed. When high order modulation is utilized, performance in the flat-fading channel model is better than ITU pedestrian B channel at low SNR regions. Spatial multiplexing is ideal for achieving very high peak rates, while transmit diversity is a valuable scheme to minimize the rate of bit error occurrence thereby improving signal quality. Read More Read Less

Abstract Currently, Multi-user Multiple-In Multiple-Out (MU-MIMO) systems are used in new generation wireless technologies. The numbers of users and applications increase rapidly owing to ongoing improvement in wireless technology. At the same time, wireless communication need the high data rate and link reliability. Therefore, MU-MIMO improvements have to consider 1) providing the high data rate and link reliability, 2) support all users in the... Currently, Multi-user Multiple-In Multiple-Out (MU-MIMO) systems are used in new generation wireless technologies. The numbers of users and applications increase rapidly owing to ongoing improvement in wireless technology. At the same time, wireless communication need the high data rate and link reliability. Therefore, MU-MIMO improvements have to consider 1) providing the high data rate and link reliability, 2) support all users in the same and frequency resource, and 3) using low power consumption. In reality, inter-user interference has a strong impact when more users access the wireless link. Complicated transmission techniques such as interference cancellation are used to maintain a given desired quality of service. Due to these problems, MU-MIMO systems with very large antenna arrays (known as massive MIMO) are proposed. The channel vectors are nearly orthogonal, and the inter-user interference is reduced significantly with massive MU-MIMO systems. Therefore, the users can be served with high data rate simultaneously. In this paper, we focus on the performance analysis of massive MU-MIMO downlink system where the base station uses linear precoding schemes to serve many users over Nakagami-m fading channel. Read More Read Less