In the attempt to respond to market demands, new techniques for wireless communication systems have been proposed to ensure, to all active users that are sharing the same network cell, an increased quality of service, regardless of any environmental factors, such as their position within the cell, time, space, climate, and noise. One example is the nonorthogonal multiple access (NOMA) technique, proposed within the 5G standard, known for supporting a massive connectivity and a more efficient use of radio resources. This paper presents two new sets of complex codes— multiple-user shared-access (MUSA) and extended MUSA (EMUSA), and an algorithm of allocation such that the intercorrelation should be as reduced as possible that can be used in MUSA for 5G NOMA-based technique scheme. Also, it analyzes the possibility of creating complex codes starting from PN (cPN), which is a novel idea proposed in this paper, whose results are promising with respect to the overall system performances. First, a description of the basic principles of MUSA are presented; next, the description of the proposed system will be provided, whose performance will be tested using Monte Carlo MATLAB simulations based on bit error rate (BER) versus signal-to-noise ratio (SNR). The system performances are evaluated in different scenarios and compared with classical code division multiple access (CDMA) having the following system parameters in sight: the number of antennas at the receiver side and the number of active users.

Smart agriculture concept uses innovative solutions including IoT and Cloud storage features, dedicated sensors for monitoring basic agricultural parameters, new communications protocols, etc. SmartAgro architecture comprises a telemetry system for Key Performance Indicators (KPIs) such as air & soil temperature, air & soil relative humidity, leaf wetness, etc. The current paper outlines the reliability of the implemented system by comparing and analyzing data collected in spring 2019 and spring 2020. The relevance of this season consists in great air variations due to the transition from winter to summer. Being monitored in a vine area near Bucharest, these data may be useful for different statistics related to grapes culture in this season and can be used by interested parties for future predictions related to vine crops. Moreover, in this paper, data fusion will allow advanced data management and coherence achievement among collected data.

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Our world is in a continuous evolution from all points of view, therefore there are new needs for which support must be provided and for which a series of new techniques have been proposed. In the field of wireless communications, we can talk about non-orthogonal multiple access (NOMA) technique, which is included in the 5G standard, that can offer an increased quality of service (QoS) to end users irrespective of their position within the cell or distortion factors. This paper presents a new set of complex spreading codes that fall in the coverage area of the 5G NOMA-based technique scheme. The creation of the new, aforementioned, set of complex codes starts from Walsh- Hadamard orthogonal spreading codes. Their performance will be tested using Monte Carlo Matlab simulations for bit error rate (BER) versus signal-to-noise ratio (SNR). The performance of the system will be tested in different scenarios, where the number of antennas at the receiver, the length of the complex spreading codes and the number of active users vary.

In this paper is investigated the performance of an uplink MIMO system when the multi-user shared access (MUSA) technique is applied. The complex spreading codes used in MUSA are created starting from the traditional PN codes that are used in the code division multiple access (CDMA) systems. We choose this approach to be sure that the obtained complex spreading codes have low correlation. The numerical results will help us conclude if our proposed method, to create complex spreading codes, is achieving the best performance when the modulated information is transmitted over a channel affected by Rayleigh fading, in an overloaded system. The results obtained by our method will be compared with the ones obtained when the complex spreading codes are created arbitrarily.