A statistical characterization of the fundamental performance bounds an intelligent reflective surface (IRS) intended for aiding wireless communications is presented. To this end, outage probability, average symbol error probability and achievable rate are derived in closed-form. By virtue asymptotic analysis high signal-to-noise ratio (SNR) regime, diversity order derived. Thereby, we show that a gain number passive elements embedded within IRS can be achieved with only controllable phase...

The sum rate performance of simultaneous transmitting and reflecting reconfigurable intelligent surface (STAR- RIS) assisted full-duplex (FD) communication systems is investigated. reflection transmission coefficients STAR- RIS elements are optimized for the energy splitting mode switching protocols to maximize weighted system. underlying optimization problems non-convex, hence, successive convex approximation technique has been employed develop efficient algorithms obtain suboptimal...

Novel user clustering and pilot assignment schemes are proposed for non-orthogonal multiple access (NOMA) aided multicell massive multiple-input multiple-output systems. Our designs leverage the spatial covariance matrices of users, they applicable to both overloaded underloaded cases. Users having linearly dependent grouped into same cluster, assigned with orthogonal pilots mitigate intra-cluster contamination. These shared among users in different clusters reduce training overhead. Then,...

In this paper, the performance of a distributed intelligent reflective surface (IRS)-aided communication system is investigated. To end, optimal signal-to-noise ratio (SNR) achievable through direct and reflected channels quantified by controlling phase-shifts IRS. This SNR statistically characterized deriving tight approximations to exact probability density function cumulative distribution for Nakagami- m fading. Thereby, outage rate bounds are derived in closed-form, they validated via...

The achievable secrecy rates for a cell-free massive multiple-input multiple-output (MIMO) in the presence of single-antenna active eavesdropper are derived and compared with that co-located MIMO. contaminates uplink channel estimates at access points (APs), downlink precoders APs constructed based on this contaminated estimates. Hence, inadvertently beamform confidential information towards during transmission. legitimate user nodes leaked into estimated/imperfect state finite infinite...

Max-min fairness optimal rate-energy trade-off of simultaneous wireless information and power transfer is derived with imperfectly estimated channels at the massive multiple-input multiple-output base-station statistical channel knowledge users. The transmit control coefficients, common harvested energy, achievable user rates are for time-switching power-splitting protocols.

The achievable sum rate of multi-cell multi-user massive multiple-input multiple-output (MIMO) downlink is investigated. Hybrid beamformers, which are constructed by using estimated/imperfect channel state information, employed at the base-station. Thus, MIMO base-station in each L cells enabled with a typical power-intensive digital precoder and quantized analog beamformer. This setup can significantly reduce number radio frequency (RF) chains required for precoder, thereby, power...

In this paper, the achievable secrecy rate of a relay-assisted massive multiple-input multiple-output (MIMO) downlink is investigated in presence multi-antenna active/passive eavesdropper. The excess degrees-of-freedom offered by MIMO base-station (BS) are exploited for sending artificial noise (AN) via random and null-space precoders. An active eavesdropper contaminates uplink channel estimates pilot sequences identical to those legitimate users/relay. This contamination makes BS implicitly...

The feasibility of utilizing a relay-assisted downlink massive multiple-input multiple-output (MIMO) to boost the performance simultaneous wireless information and power transfer (SWIPT) is investigated. key idea simultaneously transmit toward direct/relayed-users by leveraging excess degrees-of-freedom offered antenna arrays at base-station (BS). limits are established deriving harvested energies, achievable rates, energy-rate trade-offs in presence imperfectly estimated/partial channel...

The achievable rate performance of simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS) aided massive multiple-input multiple-output (MIMO) systems is investigated. Specifically, the user rates are derived for three operating protocols STAR-RIS, namely energy-splitting (ES), mode-switching (MS), time-switching (TS) with both unicast multicast transmissions. This analysis useful in evaluating system under imperfectly estimated channel state information...

The performance of massive multiple-input multiple-output (MIMO) configurations for multi-cell multi-user amplify-and-forward relay networks is investigated. Two MIMO signal processing techniques (SPT-1 and SPT-2) are proposed, their computational complexity gains compared with multi-pair relaying (SPT-3) by deriving the partial full achievable asymptotic sum rates perfect imperfect channel state information. Thereby, cumulative effects estimation errors, co-channel interference (CCI), pilot...

A generic performance analysis framework is developed for multicell amplify-and-forward (AF) multiway massive multiple-input multiple-output (MIMO) relay networks. The detrimental effects of imperfect channel state information (CSI), including estimation errors and outdated/delayed CSI MIMO AF networks, are investigated. Thereby, the first time in open literature context cumulative pilot contamination aging caused by reuse nonorthogonal sequences relative movements user nodes, respectively,...

The achievable rates of multicell/multiuser massive multiple-input multiple-output (MIMO) relay networks with underlay spectrum sharing are investigated for imperfect/perfect channel state information (CSI). transmit power constraints the secondary user nodes and relays derived. A max–min fairness optimal control algorithm is formulated, thereby, allocation coefficients maximum common detrimental effects intracell intercell pilot contamination studied three sequence designs (PSDs). Thereby,...

The detrimental effects of pilot contamination attacks by active eavesdroppers are investigated for multi-cell multi-user massive multiple-input multiple-output (MIMO) relay networks. To this end, secure transmission strategies designed both users-to-relay and relay-to-destination channels in the presence with imperfect legitimate user channel state information (CSI) no eavesdropper CSI knowledge at relay. excess degrees-of-freedom offered MIMO exploited to mitigate cooperative jamming (CJ)...

In this paper, the feasibility of adopting an intelligent reflective surface (IRS) in a cell-free wireless communication system is studied. The received signal-to-noise ratio (SNR) for IRS-enabled set-up optimized by adjusting phase-shifts passive elements. Then, tight approximations probability density function and cumulative distribution optimal SNR are derived Rayleigh fading. To investigate performance model, bounds/approximations achievable rate outage closed form. impact discrete...

The performance of non-orthogonal multiple-access (NOMA)-aided massive multiple-input multiple-output (MIMO) uplink is investigated. Spatially-distributed user nodes are grouped into multiple clusters based on spatial-directional information, and a set orthogonal pilots assigned to these clusters. To strike balance between the pilot training overhead number users that can be served simultaneously in same time-frequency resource block, NOMA-enabled within given cluster share sequence....

The performance of an intelligent reflecting surface (IRS)-assisted time-switching simultaneous wireless information and power transfer (SWIPT) system is investigated from a maxmin user-fairness perspective. A series optimization problems formulated to maximize the minimum harvested energy achievable user rates via jointly optimizing transmit powers at base-station (BS) phase-shifts IRS. underlying are non-convex, thus, efficient alternating algorithms developed obtain sub-optimal solutions....

The acquisition of channel state information is an essential step in enabling intelligent reflecting surfaces (IRSs) for wireless communications. In this letter, we introduce a novel procedure to estimate the cascaded between base station (BS), IRS, and users multi-user multiple-input single-output system. common BS-IRS channel, over which all transmit, leveraged decompose into series rank-1 matrices. Low-rank matrix recovery methods are utilized improve upon linear minimum mean-squared...

In this paper, a comprehensive performance analysis of distributed intelligent reflective surfaces (IRSs)-aided communication system is presented. First, the optimal signal-to-noise ratio (SNR), which attainable through direct and reflected channels, quantified by controlling phase shifts IRS. Next, SNR statistically characterized deriving tight approximations to exact probability density function (PDF) cumulative distribution (CDF) for Nakagami-$m$ fading. The accuracy/tightness statistical...

The performance of multi-cell massive multiple-input multiple-output (MIMO) downlink (DL) with nonorthogonal multiple access (NOMA) is investigated. A novel pilot assignment for NOMA users proposed to mitigate intra-cluster contamination and alleviate the detrimental impact inter-cluster in useful operating regime. user nodes grouped into same cluster based on spatial-direction information are assigned orthogonal pilots intracluster contamination. These shared among clusters reduce training...

Multi-cell multi-user underlay spectrum-sharing massive multiple-input multiple-output systems operating with reverse time division duplexing (R-TDD) are investigated. By primarily aiming at fully mitigating intra-cell pilot contamination and coherent interference, in the proposed R-TDD scheme, primary/secondary allowed to operate only opposite transmission directions. In order establish fundamental performance limits, secondary transmit power constraints achievable rates derived presence of...

The sum rate performance of simultaneous relay and direct massive multiple-input multiple-output (MIMO) downlink transmissions is investigated for the imperfect channel state information (CSI) case. In this context, a MIMO base-station transmits simultaneously to spatially distributed relayed user nodes by using two independent zero-forcing based precoders. uplink CSI at estimated non-orthogonal pilots transmitted nodes, hence, estimates are affected pilot contamination. To end, detrimental...

The feasibility of adopting distributed massive multiple-input multiple-output (D-MMIMO) for mitigating the achievable rate loss incurred by spatially-correlated fading at space-constrained user antenna arrays when served co-located MIMO (C-MMIMO) counterpart is investigated. In order to explore a practically-viable design, cumulative effects spatial correlation both multi-antenna access points (APs) and users, beamforming uncertainty caused imperfectly estimated channel state information...