Transmit Antenna Selection Algorithm Research Articles

Performance of Transmit Antenna Selection in Multiple Input Multiple Output-Orthogonal Space Time Block Code (MIMO-OSTBC) System Joint with Bose-Chaudhuri-Hocquenghem (BCH)-Turbo Code (TC) in Rayleigh Fading Channel

The Transmit antenna selection (TAS) technique is essential to increase the efficiency of spatial modulation (SM) systems. This TAS is an effective technique for reducing the Multiple Input Multiple Output (MIMO) systems, which can increase the computational difficulty and Bit error rate (BER) by various TAS algorithms. But these selection methods cannot provide code gain, so it is essential to join the external code in TAS to obtain code gain advantages in BER. In some existing work, the improved BER has been perceived by joining Forward Error Correction Code (FEC) and Space Time Block Code (STBC) for MIMO systems provided greater code gain. A multiple TAS-OSTBC technique with new integration of Bose–Chaudhuri–Hocquenghem (BCH)-Turbo code (TC) is proposed in this paper. The TAS-OSTBC system connects with the external BCH code in sequence of internal Turbo code. This combination can provide increasing code gain and the effective advantages of the TAS-OSTBC system. To perform the system analysis Rayleigh channel is utilized. In the case with multiple TAS-OSTBC systems, better performance can provide by this new combination of the BCH-Turbo compared to the conventional Turbo code for the Rayleigh fading.

MIMO-Orthogonal space time block code system joint with BCH-TC in Rayleigh fading channel for performance of transmit antenna selection

Purpose To enhance the performance transmit antenna selection (TAS) of spatial modulation (SM), systems technique needs to be essential. This TAS is an effective technique for reducing the multiple input multiple output (MIMO) systems computational difficulty, and bit error rate (BER) can increase remarkably by various TAS algorithms. But these selection methods cannot provide code gain, so it is essential to join the TAS with external code to obtain cy -ode gain advantages in BER. Design/methodology/approach In this paper, Bose–Chaudhuri–Hocquenghem (BCH)-Turbo code TC is combined with the orthogonal space time block code system. Findings In some existing work, the improved BER has been perceived by joining forward error correction code and space time block code (STBC) for MIMO systems provided greater code gain. The proposed work can provide increasing code gain and the effective advantages of the TAS-OSTBC system. Originality/value To perform the system analysis, Rayleigh channel is used. In the case with multiple TAS-OSTBC systems, better performance can provide by this new joint of the BCH-Turbo compared to the conventional Turbo code for the Rayleigh fading.

Adaptive Spatial Modulation over MmWave Channel with UPA

Spatial modulation (SM) utilizes the transmit antenna index and a quadrature amplitude modulation (QAM) symbol chosen from a constellation diagram to improve spectral efficiency (SE) comparing to conventional modulation scheme. However, in the conventional SM system, the modulation mode applied to the active antenna is fixed, which degrades the bits error rates (BER) and spectral efficiency (SE) performance. Moreover, a large number of researches on SM systems focus on the utilization of the uniform linear array (ULA) for transmission, which only considers the transmission on the horizontal domain while ignoring that on the vertical domain. Therefore, in this paper, we propose an adaptive spatial modulation (ASM) scheme with uniform planar array (UPA) over millimeter wave (mmWave) channels, which combines SM with adaptive modulation (AM) to enhance the performance of SE. To further improve the bits error rates (BER) performance, we develop an UPA-based ASM scheme with transmit antenna selection (TAS). We then analyse the BER and SE performance of both the two ASM scheme and obtain the closed-form expression for SE of the UPA-based ASM scheme with TAS algorithm. The simulations demonstrate that the proposed ASM schemes can achieve a considerable SE and a relatively low BER.

Multiuser Space–Time Line Code With Transmit Antenna Selection

In this paper, a multiuser space-time line code (MU-STLC) scheme is newly designed that concurrently delivers multiple STLC signals to multiple users, and a preprocessing matrix for the MU-STLC is derived based on the minimum mean square error criterion. The novel MU-STLC method retains the conventional STLC receiver structure so that each user linearly combines the received signals without using the full channel state information to decode the STLC signals. With more transmit antennas than the number of users having two receive antennas, a transmit antenna selection (TAS) scheme is investigated in combination with the proposed MU-STLC method, and the detection signal-to-interferenceplus-noise ratio (SINR) is derived depending on a specific TAS pattern. The performance improvement obtained from the TAS is significant, yet finding the optimal TAS pattern is a combinatorial problem that requires prohibitively high computational complexity. To resolve this issue, a greedy TAS algorithm is also proposed that iteratively selects the transmit antenna maximizing the detection SINR in each greedy step. The numerical results verify the efficacy of the proposed MU-STLC system with the SINR-based greedy TAS algorithm in terms of the bit error rate performance and computational complexity. For example, comparing with a scheme that selects four antennas from eight antennas randomly to support four users, the proposed TAS scheme can reduce the required signal-to-noise ratio for achieving 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> bit-error-rate by approximately 6 dB when quadrature phase-shift keying is employed. Furthermore, the proposed method can achieve comparable performance to the optimal antenna selection scheme with the reduced computational complexity by O(M <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sup> ) from O(M <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">U+3</sup> ), where M and U are the numbers of transmit antennas and selected antennas (or users), respectively.

A Novel Transmit Antenna Selection Algorithms to Improve Energy and Spectral Efficiency

In massive MIMO systems, the selection of optimal transmits antennas remains as a major constraint. As the number of antennas is increased, the power or energy consumption also increases. Selection of optimal transmit antennas is considered as a multi objective problem, where the energy has to be minimizedand the spectral efficiency (bandwidth) has to be increased. In fact, for attaining higher bandwidth, more transmit antennas have to be selected, which leads to increase in power consumption, In this proposal various papers are reviewed for Energy and Spectral Efficiency performance in Massive MIMO Technology through different algorithms and parameter comparisons are made to identify the better algorithms in terms of EE and SE to achieve the higher data transmission rates, BER, mitigating the inter Noise interference.

Transmit Antenna Optimization in Massive MIMO Technology with EE, SE Trade off

Massive MIMO Technology showed its unique characteristics and capabilities for future wireless communications where high data transmission rates are desired for fast growing 5G applications. High data transmission rates need more number of antennas at base station which comprised of increased system complexity and hardware cost. A proven method for reducing number of RF (radio frequency) chains at base station is Transmit Antenna Selection algorithm. In this paper an effective approach for TAS and optimizing the number of antennas at base station for desired data rates have been proposed and a Tradeoff between SE (Spectral Efficiency), EE (energy Efficiency) are discussed. MVGSA (modified velocity Gravitational Search algorithm) discussed for optimization of Transmit Antennas along with Improved SE and EE other effective algorithms are compared with multi objectives and data transmission rates. MVGSA proved with Improved SE and EE with Effective TAS.

MIMO 시스템을 위한 저 복잡도 송신 안테나 선택 알고리즘

MIMO 시스템을 위한 저 복잡도 송신 안테나 선택 알고리즘

The Spatial Dimming Scheme for the MU-MIMO-OFDM VLC System

Multiuser visible light communication (MU-VLC) systems utilizing multiple-input multiple-output (MIMO) and orthogonal frequency-division multiplexing (OFDM) are gaining increased attentions recently. Visible light communication (VLC) links are expected to work under different illumination conditions and, thus, the need for dimming control mechanisms. However, the traditional analog- and digital-based dimming schemes have adverse effects on the data communications performance, such as clipping distortion and the variation of the duty cycle. In this paper, spatial dimming schemes based on the zero-forcing and the minimum mean-squared error precoding schemes are proposed for direct-current biased optical OFDM based indoor MU-MIMO VLC system, and the bipolar optical OFDM signal is biased by a fixed dc level. Transmit antenna selection algorithms are designed for the optimum working light emitting diodes (LEDs) subset at each dimming level. Owing to the simultaneously exploration of the selection diversity of LEDs-based lights and the channel state information, the proposed spatial dimming schemes outperform the traditional dimming schemes, which is also verified by simulation results. Thus, the proposed schemes are shown to have a great potential to be applied in practical MU-MIMO-OFDM VLC systems.

Low‐complexity transmit antenna selection algorithm exploiting null space in spatial multiplexing UWB MIMO systems

In this paper, a new transmit antenna selection algorithm for spatial multiplexing ultra‐wideband multiple‐input multiple‐output systems is proposed. It utilizes the null space of the channel matrix spatially and temporally combined for available transmit antennas. A selection strategy is used to successively find and remove the transmit antennas having the largest contribution to the null space. Its error performance is shown to be close to that of the optimal antenna selection algorithm with low complexity. © 2017 Institute of Electrical Engineers of Japan. Published by John Wiley &amp; Sons, Inc.

A Bit-to-Symbol Mapping Scheme for Spatial Modulation With Partial Channel State Information

This letter presents a bit to symbol mapping scheme for spatial modulation multiple input single output systems. The proposed scheme relies on the transmitter knowledge of partial information about the channel’s magnitude and the phase for each transmit antenna. The aim of the proposed mapping is to minimize the hamming distance between adjacent symbols, which consequently, reduces the average bit error rate at the receiver. Monte Carlo simulation results corroborate the effectiveness of the proposed scheme as compared with the conventional and hybrid mapping schemes in the literature. As well, the proposed scheme is shown to be less complex as compared with the transmit antenna selection algorithms.

Performance of decremental antenna selection algorithms for spatial multiplexing MIMO systems with linear receiver over correlated fading channels

This study proposes enhanced suboptimal transmit antenna selection algorithms based on eigenvalue decomposition for spatial multiplexing multiple-input multiple-output (MIMO) systems with linear receivers over correlated MIMO flat fading channels. The suboptimal algorithms presented are based on the n th rooting of maximal ratio combined full channel matrix, in which the condition number significantly decreases, and the decremental selection strategy. The first algorithm exploits channel gains obtained by the channel scaling technique, and is further simplified with much lower complexity in the second algorithm. It is shown that they outperform other suboptimal algorithms in terms of bit error rate minimisation under doubly correlated channels. Moreover, their computational complexities are compared with those of other fast antenna selection algorithms. In addressing channel estimation errors on doubly correlated channels, the proposed decremental selection approaches are shown to offer more robustness than other algorithms.

Performance of Enhanced Massive Multiuser MIMO Systems Using Transmit Beamforming and Transmit Antenna Selection Techniques

In this paper, the performances of massive multiuser multiple input multiple output (MMU MIMO) system with different transmit beamforming (BF) techniques and different suboptimal transmit antenna selection (TAS) algorithms over Rayleigh fading channels are investigated. Three linear transmit BF types are considered, namely, maximum ratio transmission (MRT BF), zero forcing (ZF BF) and minimum mean square error (MMSE BF). Two TAS algorithms are considered, that are pairwise error probability minimization (PM) and the capacity maximization (CM). TAS techniques are used in order to reduce the number of radio frequency (RF) chains, system complexity, and cost. This makes MMU MIMO more applicable in beyond 4G communication systems. The simulation results show that TAS algorithms are capable of decreasing the complexity of the system while maintaining the same performance of the MMU MIMO system, complex TAS techniques are not needed at large number of RF chains, and the performance improvement due to the increase of this number is limited to a certain threshold. It also demonstrated that the MMSE BF and ZF BF bit error rate performance values are better than MRT BF values for both CM and PM TAS algorithms, but it is limited to the large number of users. On the other hand, the MRT BF technique performance is good at small Eb/N0 values for both PM and CM TAS but it is relatively less affected by increasing the number of users.

Transmit Antenna Selection for Multiple-Input Multiple-Output Spatial Modulation Systems

The benefits of transmit antenna selection (TAS) invoked for spatial modulation (SM) aided multiple-input multiple-output (MIMO) systems are investigated. Specifically, we commence with a brief review of the existing TAS algorithms and focus on the recently proposed Euclidean distance-based TAS (ED-TAS) schemes due to their high diversity gain. Then, a pair of novel ED-TAS algorithms, termed as the improved QR decomposition (QRD)-based TAS (QRD-TAS) and the error-vector magnitude-based TAS (EVM-TAS) are proposed, which exhibit an attractive system performance at low complexity. Moreover, the proposed ED-TAS algorithms are amalgamated with the low-complexity yet efficient power allocation (PA) technique, termed as TAS-PA, for the sake of further improving the system’s performance. Our simulation results show that the proposed TAS-PA algorithms achieve signal-to-noise ratio (SNR) gains of up to 9 dB over the conventional TAS algorithms and up to 6 dB over the TAS-PA algorithm designed for spatial multiplexing systems.

Further Complexity Reduction for Antenna Selection in Spatial Modulation Systems

In this letter, the transmit antenna selection in the spatial modulation system is studied. First, the computational complexity of the transmit antenna selection algorithm previously proposed elsewhere is reduced through an alternative computation of the singular value. Second, the minimum distance ascent (MDA) search is proposed to reduce the search complexity, where the initial antenna subset is acquired through the greedy incremental algorithm. Simulation results show that, compared with the exhaustive search, the proposed MDA search reduces the search complexity enormously with only slight performance loss.

A Novel Antenna Selection Algorithm Based on Port Selection in Distributed MIMO Systems

The antenna number in distributed MIMO system is much larger than that in distributed antenna system (DAS) and traditional centralized MIMO system. Therefore adopting the existing antenna selection algorithms with excellent performance will make it difficult to realize the system due to the complexity of the algorithms. In order to solve the problem, a novel antenna selection algorithm performed at the base station (BS) is proposed according to the structural characteristics of the system. In the proposed algorithm, the antenna search scope is narrowed down by port selection based on the trace of the sub-channel matrices, and antennas with little contributions to the system capacity are removed gradually by iteratively updating the optimization parameter, which further reduces the complexity. When this algorithm is treated as the transmit antenna selection algorithm, its port selection process is performed by the user equipment, which can reduce the feedback overhead. Simulation results show that the proposed algorithm possesses the similar system capacity with the optimal algorithm.

RAISE: A New Fast Transmit Antenna Selection Algorithm for Massive MIMO Systems

In this paper, we study the problem of transmit antenna selection for massive multiple-input multiple-output systems by maximizing the determinant modulus of the selected channel matrix. Based on the maximum-volume submatrix finding method, we propose a real-time antenna-by-antenna iterative swapping enhancement (RAISE) transmit antenna selection algorithm with low memory cost and low computational complexity. The convergence of the proposed algorithm is proved and the performance of it is evaluated via numerical simulations. Our results show that, compared to the traditional antenna selection algorithms, RAISE can achieve near optimal capacity performance while the computational complexity and the memory cost are significantly reduced.

Error Performance of Spatial-temporal Combining-based Spatial Multiplexing UWB Systems Using Transmit Antenna Selection

This paper applies transmit antenna selection algorithms to spatial-temporal combining-based spatial multiplexing (SM) ultra-wideband (UWB) systems. The employed criterion is based on the largest minimum output signal-to-noise ratio of the multiplexed streams. It is shown via simulations that the bit error rate (BER) performance of the SM UWB systems based on the two-dimensional Rake receiver is significantly improved by antenna diversity through transmit antenna selection on a log-normal multipath fading channel. When the transmit antenna diversity through antenna selection is exploited in the SM UWB systems, the BER performance of the spatial-temporal combining-based zero-forcing (ZF) receiver is also compared with that of the ZF detector followed by the Rake receiver.

Efficient Capacity-Based Joint Quantized Precoding and Transmit Antenna Selection Using Cross-Entropy Method for Multiuser MIMO Systems

The current paper considers the joint precoding and transmit antenna selection to reduce hardware cost, such as radio-frequency chains, associated with antennas in the downlink of multiuser multiple-input multiple-output systems with limited feedback. The joint precoding and transmit antenna selection algorithm requires an exhaustive search of all possible combinations and permutations to find the optimum solution at the transmitter, thus resulting in extremely high computational complexity. To reduce the computational load while still maximizing channel capacity, the cross-entropy (CE) method is adopted to determine the suboptimum solution. Compared with the conventional genetic algorithm and random search method, the CE method provides better performance under the same computational complexity, as shown by the simulation results.

Opportunistic Cooperation for Multi-Antenna Multi-Relay Networks

A low-complexity, near-optimal transmit antenna selection algorithm is proposed for multi-relay networks where all nodes are equipped with multiple antennas. We first establish a system model and a unified capacity maximization framework for a two-hop opportunistic relaying scheme where the source node (S) transmits signals to multiple relay nodes (R) in the first time slot, and the selected relay antennas and their corresponding relay nodes receive, decode and forward the messages to the destination (D) in the second time slot. Based on the system model, we develop a transmit antenna selection algorithm that maximizes the network capacity assuming that the channel state information is available at the receivers but not available at the transmitters, and total transmit power constraints are imposed on source/relay transmitters. The proposed algorithm first constructs a sorted list of relay antennas with decreasing S-R capacities, then iteratively maximizes the R-D capacity over a candidate antenna set using a low-complexity, near-optimal antenna selection scheme. The candidate set is reduced in the next iteration according to the selected antenna set of the current iteration. The overall network capacity is computed for the selected antenna sets of all iterations, and the set yielding the highest S-R-D capacity is the solution to the maximization problem. We show that this novel iterative algorithm achieves near-optimal solution and has a polynomial-time complexity. We also derive the lower and upper bounds of the achievable network capacity for both average capacity and outage capacity. Numerical examples show the significant performance gains obtained via the proposed scheme compared to its conventional counterparts.

Performance evaluation of spatially multiplexed MIMO systems with subset antenna transmission in interference limited environments

Transmit antenna selection in spatially multiplexed multiple-input multiple-output (MIMO) systems is a low complexity low-rate feedback technique, which involves transmission of a reduced number of streams from the maximum possible to improve the error rate performance of linear receivers. It has been shown to be effective in enhancing the performance of single-user interference-free point-to-point MIMO systems. However, performance of transmit antenna selection techniques in interference-limited environments and over frequency selective channels is less well understood. In this paper, we investigate the performance of transmit antenna selection in spatially multiplexed MIMO systems in the presence of co-channel interference. We propose a transmission technique for the downlink of a cellular MIMO system that employs transmit antenna selection to minimize the effect of co-channel interference from surrounding cells. Several transmit antenna selection algorithms are proposed and their performance is evaluated in both frequency flat and frequency selective channels. Various antenna selection algorithms proposed in the literature for single user MIMO links are extended to a cellular scenario, where each user experiences co-channel interference from the other cells (intercell interference) in the system. For frequency selective channels, we consider orthogonal frequency division multiplexing (OFDM) with MIMO. We propose a selection algorithm that maximizes the average output SINR over all subcarriers. A method to quantify selection gain in frequency selective channel is discussed. The effect of delay spread on the selection gain is studied by simulating practical fading environments with different delay spreads. The effect of the variable signal constellation sizes and the number of transmitted streams on the bit error rate (BER) performance of the proposed system is also investigated in conjunction with the transmit antenna selection. Simulation results show that for low to moderate interference power, significant improvement in the system performance is achievable with the use of transmit antenna selection algorithms. Even though the gain due to selection in frequency selective channels is reduced compared to that in flat fading channels due to the inherent frequency diversity, the performance improvement is significant when the system is interference limited. The performance improvement due to reduced number of transmit streams at larger signal constellation sizes is found to be more significant in spatially correlated scenarios, and the gain due to selection is found to be reduced with the increased delay spread. It is found that employing transmit antenna selection algorithms in conjunction with adaptation of the number of transmitted streams and the signal constellation sizes can significantly improve the performance of MIMO systems with co-channel interference.