Spatial Division Multiplexing Research Articles

Amplification technology for spatial division multiplexing signals transmitted using multicore fibres

AbstractAmplification technologies needed for spatial division multiplexing (SDM) signal transmission have been reported, especially focusing on submarine systems, which have stricter requirements than terrestrial ones. As the first step of a large‐scale commercialisation, 2‐core un‐coupled (UC) fibre production has already been announced. However, optical amplifiers for SDM signals are still under investigation because SDM amplifiers have various architectural possibilities, depending on the requirements to be considered in designing systems. The multicore erbium‐doped fibre amplifier (MC‐EDFA) architecture is classified from the viewpoint of the number of erbium‐doped fibre (EDF) cores and its pumping method. Core pumped MC‐EDFA is more compatible with the conventional single‐core fibre (SCF)‐ based system and more mature than cladding pumped MC‐EDFA. However, cladding pumped MC‐EDFA has a unique feature of collective amplification of all cores in a single multicore fibre (MCF) and the potential of large‐scale integration of amplification cores in a single package. For a feasibility study, a C‐band 19‐core cladding pumped MC‐EDFA prototype is fabricated using a 19‐core isolator. A half volume of the equivalent conventional single‐core (SC‐) EDFA is successfully demonstrated. One unique feature of UC‐MCF is bidirectional (BD‐) transmission using a single UC‐MCF. Signal transmission direction can differ from core to core. This feature is useful for efficiently accommodating traffic of asymmetric communication data and expanding transmission capacity at a constant transmission distance. A C‐band 7‐core cladding pumped BD‐MC‐EDFA prototype is fabricated for the bidirectional MCF transmission line. Experimental results show transmission capacity was expanded by 17% using the prototype when bidirectional signal assignment was adapted. Towards practical use, optical components suitable for MC‐EDFA need to be developed to draw out potential advantages of SDM technologies.

Advanced optical transceiver and switching solutions for next-generation optical networks

Innovative transceiver and switching approaches should be explored with special focus on flexibility, energy efficiency, sustainability, and interoperability to be adopted on next-generation 6G optical networks driven by the diverse landscape of emerging applications and services and increasing traffic demand. In this regard, multiband (MB) and spatial division multiplexing (SDM) technologies arise as promising technologies for providing suitable network capacity scaling while fulfilling the stringent requirements of the incoming 6G era. In this paper, innovative MB over SDM (MBoSDM) switching node and sliceable bandwidth/bit rate variable transceiver (S-BVT) architectures with enhanced capabilities and features are proposed and experimentally validated. Different network scenarios have been identified and assessed, enabling up to 180.9 Gb/s S+C+L transmission in back-to-back (B2B) configuration. A MBoSDM scenario including both transceiver and switching solutions is demonstrated, including a 19-core multi-core fiber (MCF) of 25.4 km. Thanks to the transceiver modular and scalable approach, higher capacities can be envisioned by enabling multiple slices working in the different bands beyond the C-band. A power efficiency analysis of the proposed transceiver is also presented, including a pathway towards the integration with a software defined networking (SDN) control plane assisted by energy-aware artificial intelligence (AI)/machine learning (ML) trained models.

Optimizing Spatial Channel Networks (SCNs) in Hierarchical Optical Cross-Connect (HOXC) architectures: Impact of wavelength switching granularity on performance

The increasing demand for network bandwidth highlights the critical need to enhance optical transmission systems. Utilizing the entire C-band for a single optical channel(OCh) eliminates the requirement for wavelength switching, prompting the emergence of spatial channel networks (SCNs). SCNs transform the optical layer into hierarchical spatial division multiplexing (SDM) and wavelength division multiplexing (WDM) layers through the implementation of hierarchical optical cross-connects (HOXCs). A HOXC comprises a spatial channel cross-connect (SXC) for spatial bypass switching and multiple wavelength cross-connects (WXCs) for wavelength channel switching, ensuring efficient optical transmission. Therefore, the design of the HOXC plays a pivotal role in determining both the device cost and network performance in SCNs. This study investigates the impact of wavelength switching granularity on core-selective switch (CSS)-based HOXC architectures. We propose an adaptive dynamic Routing, Spatial Channel, and Spectrum Assignment (RSCSA) algorithm to solve routing and resource allocation problems in SCNs. By examining SCN designs with varying wavelength switching granularities, we assess the overall network deployment cost, considering both network throughput and spectrum resource utilization. Our findings indicate that adjusting the granularity of wavelength switching in SCNs can significantly affect device costs and performance, highlighting the importance of identifying an optimal SCN design that strikes a balance between these factors. These insights offer valuable guidance for the practical planning and management of future SCN deployments.

Spatial Mode Division Multiplexing of Free-Space Optical Communications Using a Pair of Multiplane Light Converters and a Micromirror Array for Turbulence Emulation

Multi-plane light converters (MPLC) are a means of deconstructing a wavefront into constituent modes that are focused at specific spatial locations, and the reverse—that specific inputs result in controlled modal output. We have used a pair of MPLCs with 21 Hermite–Gaussian modes to represent a free-space optical connection. The effects of strong atmospheric turbulence (Cn2 = 10−13 m−2/3) are emulated using a micromirror array producing a time sequence of aberrating frames. The modal crosstalk between transmitter and receiver modes induced by the turbulence is presented by measuring the intensity in receiver channels for the same turbulence. Six receiver modes are used for optical communication channels with a rate of 137 Gbits/s displaying the benefits of single input multiple output (SIMO) operation for overcoming the deleterious effects of turbulence.

A novel multicore Er/Yb co-doped microstructured optical fiber amplifier with peanut-shaped air holes cladding

Abstract The multicore fiber amplifier, as a key component in spatial division multiplexing (SDM) communication systems, presents higher technical difficulty compared to traditional multi-channel single core fiber amplifiers, which has sparked widespread attention. To achieve balance, efficiency, miniaturization, and cost-effectiveness in the performance of multi-core optical fiber amplifiers, we propose an innovative triple cladding 13-core Er/Yb co-doped microstructured fiber (13CEYDMOF). The proposed fiber features an outer cladding with peanut-shaped air holes, which enables uniform excitation of the 13 cores using a single multimode laser pump source within the inner cladding. This approach also prevents damage or aging of the fiber’s outer coating due to the pump laser. Furthermore, the design of Peanut-Shaped Air Holes effectively increases the numerical aperture (NA) of the inner cladding while reducing the outer diameter of the fiber, enhancing the fiber’s mechanical flexibility. To address the coupling difficulties caused by air holes, we bi-directionally pump the 13CEYDMOFA by utilizing a combined technique of the side winding and end pumping. The experimental results show that the 13CEYDMOFA can achieve an average gain of 23.8 dB, a noise figure (NF) of ∼4.6 dB, and an inter-core gain difference of less than 2 dB in the wavelength range of 1529–1565 nm. The in-line amplified transmission experiment demonstrates that the 13CEYDMOFA is well suited for the 13 spatial channels transmission. To the best of our knowledge, this is the first time to realize high performance telecommunication band amplification in a multicore microstructure fiber.

M-type refractive index profile erbium-doped fiber for high-efficiency multicore EDFA.

Cladding-pumped multicore erbium-doped fiber is an important element for future spatial division multiplexing (SDM) amplification. We propose an M-type erbium-doped multicore fiber to achieve high-efficiency SDM amplification. The performance of cladding-pumped erbium-doped fiber with a central refractive index depression has been investigated, and the M-type fiber has better amplification performance than conventional fibers by reducing the signal mode overlap with the doped region. The experiment results show that the M-type 4-core erbium-doped fiber has a gain improvement of 2.8 dB compared with conventional 4-core fiber. The pump conversion efficiency (PCE) has been enhanced from 4.47% to 8.01%. For a 7.0 W pump power at 976 nm, the M-type fiber exhibits an average gain of 20.0 dB and an average noise fiber of 6.8 dB at the L-band. The core-to-core gain variation is less than 1.6 dB.

MACHINE LEARNING APPLICATION IN INVERSE DESIGN OF FEW-MODE FIBERS

The importance of optical fiber research is increasing due to its applications in the digital world, including components, sensors, and high data rate communication. Few-mode fiber (FMF) research is regenerating due to its high data rate transmission ability. This dissertation work proposes new designs of FMFs with updated material composition and geometry to establish weakly coupled spatial division multiplexing (SDM)/mode division multiplexing (MDM) links. The next generation of communication, 5G aims to connect people and things via intelligent networks, but current network architectures struggle to handle massive data traffic. The spatial domain of the fiber is highly useful for handling this massive data traffic. This work reviews the requirements of 5G networks and how they can be handled through spatial multiplexing and mode multiplexing through a few-mode optical fiber. The article demonstrates machine learning-based inverse modeling of the triangular-ring-core few-mode fiber profile with weak coupling optimization.

Post-FEC performance evaluation of optical SDM systems with mode-dependent loss

This work is focused on the bit error rate (BER) performance of spatial division multiplexing (SDM) systems over an optical channel with mode-dependent loss or gain (collectively referred to in this paper as MDL). When the latter is non-negligible, the BER has a random nature that introduces the outage probability as an important performance metric for the system design and also impacts on the selection of a forward-error correction (FEC) scheme. In MDL-impaired SDM systems, the pre-FEC BER is a random variable whose probability density function (PDF) and coding gain depend on the signal-to-noise ratio (SNR) at the receiver input. Hence, the common and simple approach of adding a coding gain factor to the pre-FEC BER to obtain the post-FEC BER is not adequate, and numerical simulations are needed. In this paper, we simulate and analyze the performance in terms of post-FEC BER for two proposals of applying low-density parity check (LDPC) FEC encoder/decoder in a SDM system MDL-impaired and an optimal linear multiple input multiple output (MIMO) receiver. In the first one, the LDPC is applied independently to each mode, and in the second one, the LDPC is applied among all SDM modes. Simulation results indicate that the first proposal outperforms the second. Simplifications in the log-likelihood ratio (LLR) computations have also been considered.

The Multiband over Spatial Division Multiplexing Sliceable Transceiver for Future Optical Networks

In the last 15 years, global data traffic has been doubling approximately every 2–3 years, and there is a strong indication that this pattern will persist. Hence, also driven by the emergence of new applications and services expected within the 6G era, new transmission systems and technologies should be investigated to enhance network capacity and achieve increased bandwidth, improved spectral efficiency, and greater flexibility to effectively accommodate all the expected data traffic. In this paper, an innovative transmission solution based on multiband (MB) over spatial division multiplexing (SDM) sliceable bandwidth/bitrate variable transceiver (S-BVT) is implemented and assessed in relation to the provision of sustainable capacity scaling. MB transmission (S+C+L) over 25.4 km of 19-cores multicore fibre (MCF) is experimentally assessed and demonstrated achieving an aggregated capacity of 119.1 Gb/s at 4.62×10−3 bit error rate (BER). The proposed modular sliceable transceiver architecture arises as a suitable option towards achieving 500 Tb/s per fibre transmission, by further enabling more slices covering all the available S+C+L spectra and the 19 cores of the MCF.

Spatial Division Multiplexing for Multiplex Coherent Anti-Stokes Raman Scattering

Spatial Division Multiplexing for Multiplex Coherent Anti-Stokes Raman Scattering

Free Space Optical Communication: An Enabling Backhaul Technology for 6G Non-Terrestrial Networks

The deployment of non-terrestrial networks (NTNs) is envisioned to achieve global coverage for 6G and beyond. In addition to space nodes, aerial NTN nodes such as high-altitude platform stations (HAPSs) and rotary-wing unmanned aerial vehicles (UAVs) could be deployed, based on the intended coverage and operational altitude requirements. NTN nodes have the potential to support both wireless access and backhauling. While the onboard base station provides wireless access for the end users, the backhauling link connects the airborne/space-borne base station to the core network. With its high data transmission capability comparable to fiber optics and its ability to operate in the interference-free optical spectrum, free space optical (FSO) communication is ideally suited to backhauling requirements in NTNs. In this paper, we present a comprehensive tutorial on airborne FSO backhauling. We first delve into the fundamentals of FSO signal transmission and discuss aspects such as geometrical loss, atmospheric attenuation, turbulence-induced fading, and pointing errors, all of which are critical for determining received signal levels and related link budget calculations. Then, we discuss the requirements of airborne backhaul system architectures, based on use cases. While single-layer backhaul systems are sufficient for providing coverage in rural areas, multi-layer designs are typically required to establish connectivity in urban areas, where line of sight (LoS) links are harder to maintain. We review physical layer design principles for FSO-based airborne links, discussing both intensity modulation/direct detection (IM/DD) and coherent modulation/coherent demodulation (CM/CD). Another critical design criteria for airborne backhauling is self-sustainability, which is further discussed in our paper. We conclude the paper by discussing current challenges and future research directions. In this context, we discuss reconfigurable intelligent surfaces (RIS) and spatial division multiplexing (SDM), for improved performance and an extended transmission range. We emphasize the importance of advanced handover techniques and scalability issues for practical implementation. We also highlight the growing role of artificial intelligence/machine learning (AI/ML) and their potential applications in the design and optimization of future FSO-based NTNs.

An efficient asynchronous spatial division multiplexing router for network-on-chip on the hardware platform

The quasi-delay-insensitive (QDI) based asynchronous network-on-chip (ANoC) has several advantages over clock-based synchronous network-on-chips (NoCs). The asynchronous router uses a virtual channel (VC) as a primary flow-control mechanism however, the spatial division multiplexing (SDM) based mechanism performs better over input traffics over VC. This manuscript uses an asynchronous spatial division multiplexing (ASDM) based router for NoC architecture on a field-programmable gate array (FPGA) platform. The ASDM router is configurable to different bandwidths and VCs. The ASDM router mainly contains input-output (I/O) buffers, a switching allocator, and a crossbar unit. The 4-phase 1-of-4 dual-rail protocol is used to construct the I/O buffers. The performance of the ASDM router is analyzed in terms of lower urinary tract symptoms (LUTs) (chip area), delay, latency, and throughput parameters. The work is implemented using Verilog-HDL with Xilinx ISE 14.7 on artix-7 FPGA. The ASDM router achieves % chip area and obtains 0.8 ns of latency with a throughput of 800 Mfps. The proposed router is compared with existing asynchronous approaches with improved latency and throughput metrics.

BER analysis of an optimum MIMO linear receiver in optical SDM systems with mode-dependent loss.

Multiple-input multiple-output (MIMO) receivers designed to optimize the minimum mean square error (MMSE) are a common choice in coherent optical communication systems based on spatial division multiplexing (SDM). This kind of receivers naturally integrate both MIMO equalization and matched filtering functions. However, when the optical channel exhibits significant mode-dependent loss (MDL) and/or mode-dependent gain (MDG), the impact of inter-symbol interference (ISI) and crosstalk that arise, even using an ideal MIMO MMSE linear receiver, is barely analyzed. Moreover, due to the random nature of the MDL/MDG model, the resulting ISI, crosstalk, and bit error rate (BER) also become random variables and, hence the system performance is more unpredictable. In this paper, we first evaluate the residual distortion (ISI and crosstalk) after the MIMO receiver and then we study the validity of assuming it as an additional Gaussian noise term independent of the channel noise. Next, the probability density distribution (PDF) of the BER is analyzed, from both an analytical perspective and numerical simulations. For the latter, we use a single-carrier 2-PAM (pulse amplitude modulation) system, with pulse shaping, and the MIMO MMSE receiver implementation by means of a MIMO fractionally-spaced equalizer (FSE). We carry out simulations of the system under different conditions of MDL/MDG level and signal to noise ratio (SNR), measured at the receiver input. Additionally, we address possible fits of the BER PDF to known closed-form distributions, among which the Generalized Extreme Value (GEV) family of distributions is selected, and polynomial functions are proposed that relate the system parameters with the GEV PDF parameters. Finally, we present contour maps of BER according to a giving target of system outage probability (OP) that depend on the MDL/MDG and SNR conditions.

Flexible Data Rate Allocation Using Non-Orthogonal Multiple Access (NOMA) in a Mode Division Multiplexing (MDM) Optical Power Splitter for System-on-Chip Networks.

We put forward and demonstrate a silicon photonics (SiPh)-based mode division multiplexed (MDM) optical power splitter that supports transverse-electric (TE) single-mode, dual-mode, and triple-mode (i.e., TE0, TE1, and TE2). An optical power splitter is needed for optical signal distribution and routing in optical interconnects. However, a traditional optical splitter only divides the power of the input optical signal. This means the same data information is received at all the output ports of the optical splitter. The powers at different output ports may change depending on the splitting ratio of the optical splitter. The main contributions of our proposed optical splitter are: (i) Different data information is received at different output ports of the optical splitter via the utilization of NOMA. By adjusting the power ratios of different channels in the digital domain (i.e., via software control) at the Tx, different channel data information can be received at different output ports of the splitter. It can increase the flexibility of optical signal distribution and routing. (ii) Besides, the proposed optical splitter can support the fundamental TE0 mode and the higher modes TE1, TE2, etc. Supporting mode-division multiplexing and multi-mode operation are important for future optical interconnects since the number of port counts is limited by the chip size. This can significantly increase the capacity besides wavelength division multiplexing (WDM) and spatial division multiplexing (SDM). The integrated SiPh MDM optical power splitter consists of a mode up-conversion section implemented by asymmetric directional couplers (ADCs) and a Y-branch structure for MDM power distribution. Here, we also propose and discuss the use of the Genetic algorithm (GA) for the MDM optical power splitter parameter optimization. Finally, to provide adjustable data rates at different output ports after the MDM optical power splitter, non-orthogonal multiple access-orthogonal frequency division multiplexing (NOMA-OFDM) is also employed. Experimental results validate that, in three modes (TE0, TE1, and TE2), user-1 and user-2 achieve data rates of (user-1: greater than 22 Gbit/s; user-2: greater than 12 Gbit/s) and (user-1: greater than 12 Gbit/s; user-2: 24 Gbit/s), respectively, at power-ratio (PR) = 2.0 or 3.0. Each channel meets the hard-decision forward-error-correction (HD-FEC, i.e., BER = 3.8 × 10-3) threshold. The proposed method allows flexible data rate allocation for multiple users for optical interconnects and system-on-chip networks.

Efficient Integrated Multimode Amplifiers for Scalable Long-Haul SDM Transmission

Scaling up cable capacity in a power- and cost-efficient manner is a goal of spatial-division multiplexing (SDM) in long-haul optical communication systems. Integration is a key to scaling SDM beyond the parallel single-mode fiber paradigm. Multicore or multimode fiber systems promise higher integration, but native multicore or multimode amplifiers pose challenges in efficient coupling of pump light into the amplifier, and in control of mode-dependent gain (MDG). We propose an integrated multimode amplifier design for signals in six spatial modes (12 spatial and polarization modes) that relies on excitation of only four pump spatial modes at 980 nm. Simulations of an exemplary amplifier predict a relatively flat gain above 10 dB, noise figure below 5 dB, and MDG standard deviation below 0.1 dB over the C-band (1530–1565 nm), with a power-conversion efficiency close to 30%. Key design features include a graded-index multimode fiber amplifier with optimized ring erbium doping profile, length and pump mode powers; and a cascade of wavelength- and mode-selective couplers that efficiently couples four pump diodes to four pump modes, while passing signal modes with minimal loss. Our design approach, which uses fewer pump diodes per signal mode than parallel single-mode systems, may provide an option for efficient, economical scaling of SDM long-haul systems.

Biased-Power Allocation and Shared-Antenna Selection Techniques for Spatial Modulation-Based Layer Division Multiplexing Systems

This study proposes two approaches for improving the effectiveness of spatial modulation integrated into layer division multiplexing (SM-LDM) in broadcasting systems: biased-power allocation (Bi-PA) and shared antenna selection (SAS). Even though different data rates are employed in SM-LDM systems, Bi-PA enhances bit error rate (BER) fairness across layers. The ideal power ratios are adaptively determined by balancing signal-to-interference plus noise ratios with a preference for the lower layer (LL) that involves a higher modulation order. SAS alleviates the complexity of successive interference cancellation and enhances spectral and energy efficiencies. Both the LL and upper layer (UL) share the antenna selection decision and transmit using a single antenna. The UL carries a space shift keying signal while the entire power is allocated for the LL. We analyze the spectral efficiency for the SAS-based SM-LDM system with finite alphabet inputs. Numerical results demonstrate the advantages of the proposed approaches. Compared to pre-assigned-PA (Pre-PA), Bi-PA shows nearly identical BERs for both layers and solves the error floor problem. The sharing property and common layer transmission of SAS-based SM-LDM yield a significant BER reduction relative to conventional SM-LDM. It provides gains ranging from 7 to 15 dB for LL at BER equal to 10−3, while UL performance ranges from slight gain to minor loss. Furthermore, both Bi-PA and SAS techniques enhance the achievable LL rate and sum-rate at low and intermediate signal-to-noise ratio values. They can achieve an improvement of up to two bits in LL rate and less than one bit in sum-rate at a signal-to-noise ratio of −0.5 dB. These findings show that both proposed techniques have a considerable impact on enhancing the fairness, BER performance, and feasible rates of SM-LDM systems, making them promise for broadcast system designs.

Generation of Photon Orbital Angular Momentum and Its Application in Space Division Multiplexing

In the last three decades, light’s orbital angular momentum (OAM) has been of great interest because it has unique characteristics that make it sought after in many research fields, especially in optical communications. To address the exponentially increasing demands for higher data rates and capacity in optical communication systems, OAM has emerged as an additional degree of freedom for multiplexing and transmitting multiple independent data streams within a single spatial mode using the spatial division multiplexing (SDM) technology. Innumerable research findings have proven to scale up the channel capacity of communication links by a very high order of magnitude, allowing it to circumvent the reaching of optical fiber’s non-linear Shannon limit. This review paper provides a background and overview of OAM beams, covering the fundamental concepts, the various OAM generators, and the recent experimental and commercial applications of the OAM-SDM multiplexing technique in optical communications.

Bidirectional Cladding-Pumped Multicore EDFA and its Optimization for Energy Efficiency by Tuning Pump Condition

This work investigates the feasibility of improving the energy efficiency of a cladding-pumped multicore (MC) EDFA by utilizing bidirectional (BD) pumping. We combined a conventional forward-cladding-pumped MC-EDFA with backward cladding pumping and tuned the pump-gain characteristics and gain shape by controlling the optical pump power ratio of its forward and backward pumps. Since EDFAs have wavelength dependence, output power equalization by each wavelength channel is extremely important for amplifying the wavelength division multiplexing (WDM) signal. The standard method of current equalization is to adjust the attenuation by the output power of each wavelength channel. The main issue with the current standard equalization is the indispensable optical power loss caused the reduced optical amplification efficiency of the EDFA. Our previous work demonstrated that the optical power loss due to equalization can be reduced by controlling the optical power ratio of the forward and backward pumps. This leads to improved energy efficiency of the signal amplification and equalization of both the WDM and spatial division multiplexing (SDM). <p xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">In this paper, we report our detailed investigation into the tuning amplification characteristics of the BD-MC-EDFA. Our main focus was the gain, noise figure (NF), and gain shape of a 7-core BD-MC-EDFA prototype when forward and backward optical pump power was changed. Under 8 W of total optical pump power, the percentage of 60% forward cladding optical pump power was found to be optimal for efficiency considering the minimum output optical power loss due to equalization. This condition translates into a 1.7% pump conversion efficiency (PCE) improvement, which corresponds to a 24% reduction of the total optical pump power compared to conventional MC-EDFA with only forward cladding pumping. Although the NF deteriorated by 1.0 dB in wavelength average in the 4.5-THz signal bandwidth in exchange for the efficiency improvement, degradation of the 34.2-GBaud polarization multiplexed 16 quadrature amplitude modulation (PM-16QAM) signal amplified by the BD-MC-EDFA operated under the optimized condition was negligible.

Multipath Quasi-Distributed Acoustic Sensing Based on Space Division Multiplexing and Time-Gated OFDR

Quasi-distributed optic sensing system has been widely utilized in various applications for its simple configuration, high sensing resolution, and long sensing range. In large sensing network, multipath sensing arrays are needed to be monitored simultaneously. This paper proposes a multi-path quasi-distributed acoustic sensing system based on time-gated digital optical frequency domain reflectometry (TGD-OFDR) and spatial division multiplexing (SDM) technique. The single mode fiber segment between weak reflectors is efficiently used. In experiments, vibrations on two weak reflectors array are detected simultaneously, and crosstalk between pathes is analyzed. This multi-path system does not require additional hardware equipment and the bandwidth of the system is not sacrificed, which has great potential in large-scale sensing network.

Deep learning based MIMO systems using open-loop autoencoder

This article introduces two novel multiple input multiple output spatial division multiplexing (MIMO-SDM) systems based on deep learning techniques using bit-wise (BW) and symbol-wise (SW) open-loop autoencoders (AE), abbreviated as SWAE-MIMO and BWAE-MIMO. Based on the detection methods, we introduce three detectors at the receiver: Radio Transformation Network (RTN), Minimum Mean Square Error (MMSE) technique, and the combination of MMSE technique and neural network (MMSEnet), which can suppress co-channel interference (CCI) among received signal streams resulting in low bit error rates (BER). Furthermore, the considered systems are trained in a single phase to optimally synchronize the transmitter’s and receiver’s learning parameters, thus successfully exploiting spatial diversities to improve the error performance of conventional MIMO systems using the MMSE detector with different numbers of transmit-receive antennas. In a specific case, the BWAE-MIMO system using the RTN detector (BWAE-MIMO-RTN) achieves a BER comparable to that of the conventional MIMO system with a maximum likelihood detector (MIMO-ML) when both systems are equipped with two transmitting and receiving antennas.