Amplitude Modulation Signals Research Articles

23.1-Gb/s 135-GHz Wireless Transmission Over 4.6-Km and Effect of Rain Attenuation

In this article, we have experimentally demonstrated a fiber-wireless-integration <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$D$</tex-math> </inline-formula> -band (110–170 GHz) transmission system. To extend the wireless transmission distance while maintaining the wireless bit rate as high as possible, we designed high-gain lens horn antenna modules consisting of a pair of dielectric plano-convex lenses and horn antennas for long-haul wireless links. In addition, we employ the Volterra nonlinear equalization (VNE) algorithm based on the multiple-input–multiple-output (MIMO) structure to precisely compensate for the in-phase/quadrature (I/Q) imbalance and nonlinear impairment of quadrature amplitude modulation (QAM) signals mainly caused by photoelectric (O-E) conversion and electric-photo (E-O) conversion. Meanwhile, one of the methods adopted in our experiment to decrease the influence of nonlinearity on high-order QAM signals is coupling the high-order modulation format with the probabilistic shaping (PS) technology. As a result of outdoor field experimental verification, the demonstration at 135 GHz carrier with a net rate of 23.1 Gb/s over 10 km optic-fiber and 4.6 km wireless transmission distance has been successfully carried out. It is, as we know, the first time that a record-breaking product of net bit rate and wireless transmission distance, i.e., 23.1 Gb/s <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times$</tex-math> </inline-formula> 4.6 km <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$=$</tex-math> </inline-formula> 106.3 Gb/s <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\cdot$</tex-math> </inline-formula> km, has been accomplished based on a fiber-wireless-integration system. Also, for the first time, we have measured the effect of rain attenuation for the 135 GHz millimeter-wave (mm-wave) wireless link and established more accurate rainfall models for the Shanghai region of China by comparing them with multiple rainfall models. This work can be used as a complement to the International Telecommunication Union-Radiocommunication sector (ITU-R) recommendations.

Performance vs. complexity in NN pre-distortion for a nonlinear channel.

Optical communications at high bandwidth and high spectral efficiency rely on the use of a digital-to-analog converter (DAC). We propose the use of a neural network (NN) for digital pre-distortion (DPD) to mitigate the quantization and bandlimited impairments from a DAC in such systems. We experimentally validate our approach with a 64 Gbaud 8-level pulse amplitude modulation (PAM-8) signal. We examine the NN-DPD training with both direct and indirect learning methods. We compare the performance with typical Volterra, look-up table (LUT) and linear DPD solutions. We sweep regimes where nonlinear quantization becomes more prominent to highlight the advantages of NN-DPD. The proposed NN-DPD trained via direct learning outperforms the Volterra, LUT and linear DPDs by almost 0.9 dB, 1.9 dB and 2.9 dB, respectively. We find that an indirect learning recurrent NN offers better performance at the same complexity as Volterra, while a direct learning recursive NN pushes performance to a higher level than a Volterra can achieve.

High radiation performance and multi-band acoustically driven piezoelectric antenna based on energy trapping theory

The paper introduces a novel design method for an acoustically driven piezoelectric antenna with high radiation performance and broadband characteristics based on energy trapping theory. The reasonableness of the design method is demonstrated by analytically deriving the radiated magnetic field, radiated efficiency and resonant frequency, which are further validated by simulation analysis. Furthermore, a prototype is fabricated and measured, and the results indicate remarkable improvements compared to the non-energy trapping mode, the bandwidth is widened by 10%, the radiation efficiency is increased by 28%, the radiation magnetic field is increased by three times, the transmission distance is increased by 2.75 times. The radiation enhancement and multi-band capability of the proposed antenna has been successfully demonstrated. Additionally, we have successfully implemented amplitude modulation signals transmission using proposed antenna. These results highlight the significant potential of the proposed antenna for portable, miniaturized, and high-performance wireless communication devices.

High cost-effective photonic assisted in-band interference cancellation scheme for centralized radio access network towards future 5G communication

A photonic-assisted scheme capable of self-interference cancellation (SIC) and image rejection mixing (IRM) is demonstrated to solve the intractable problem of in-band interference for in-band full duplex (IBFD) systems with high frequency and large bandwidth. In the proposed scheme, a single optical path configuration is constructed based on an integrated modulator applied as the main device. The SIC operation is implemented in the optical domain making it immune to the influence caused by fiber dispersion. Owing to the intermediate frequency (IF) signal amplitude regulation mechanism under the combined action of fiber dispersion induced phase and double sideband (DSB) modulation, the scheme can realize IRM without increasing the system complexity. Experimental results show that the 50 MHz 16-quadrature amplitude modulation (16-QAM) signal of interest (SOI) centered at different frequencies are down-converted to 2.5 GHz. The depth of SIC and image-rejection (IR) is over 35 dB and 25 dB after transmitted through a span of 10.1 km optical fiber. The received 16-QAM down-converted signal can be recovered with an error vector magnitude (EVM) which satisfies the requirement of 3GPP-specified EVM limit. The signal recovery performance, SIC depth and image rejection ratio (IRR) under different signal to interference ratio (SIR) is also investigated. In addition, a comparison of relevant literature with this scheme from the perspective of technical discussion is also presented. The proposed scheme can realize effective functional integration with compact structure, simple parameter tuning mechanism, improved stability and high cost-effectiveness to solve the in-band interference problem which is of great value to be applied in IBFD centralized radio access networks (CRAN) towards future 5G communication.

Adaptive decision threshold for an optical multipath-interference-impaired short-reach 50-Gbps PAM4 transmission.

The short-reach optical transmission systems based on intensity modulation and direct detection (IM/DD) are gradually evolving into the networks with complex link topologies and connections, especially inside the data center. Multipath interference (MPI) introduces irregular fluctuations in the 4-level pulse amplitude modulation (PAM4) signals and therefore affects the transmission performance. This Letter proposes an adaptive decision threshold (ADT) scheme to dynamically update the decision threshold, which can track the signal fluctuations in real time and mitigate the impact of MPI noise on the transmitted PAM4 signals. Numerical simulation results present that the proposed ADT scheme can significantly improve the bit error rate (BER) performance of the MPI-impaired PAM4 transmission system considering different MPI levels and laser linewidths. In a 50-Gbps PAM4 transmission system, the ADT can improve the MPI tolerance by more than beyond 6 dB when the BER reaches the KP4-forward error correction (FEC) criterion (2.4 × 10-4), presenting a better denoising performance than the existing MPI-mitigation algorithms A1 and A2. Moreover, the ADT scheme offers a lower computation complexity compared with A1 and A2, making it more practical for implementation.

Seasonal Dependence of the Pacific–North American Teleconnection Associated with ENSO and Its Interaction with the Annual Cycle

Abstract The Pacific–North American (PNA) teleconnection pattern is one of the prominent atmospheric circulation modes in the extratropical Northern Hemisphere, and its seasonal to interannual predictability is suggested to originate from El Niño–Southern Oscillation (ENSO). Intriguingly, the PNA teleconnection pattern exhibits variance at near-annual frequencies, which is related to a rapid phase reversal of the PNA pattern during ENSO years, whereas the ENSO sea surface temperature (SST) anomalies in the tropical Pacific are evolving much slower in time. This distinct seasonal feature of the PNA pattern can be explained by an amplitude modulation of the interannual ENSO signal by the annual cycle (i.e., the ENSO combination mode). The ENSO-related seasonal phase transition of the PNA pattern is reproduced well in an atmospheric general circulation model when both the background SST annual cycle and ENSO SST anomalies are prescribed. In contrast, this characteristic seasonal evolution of the PNA pattern is absent when the tropical Pacific background SST annual cycle is not considered in the modeling experiments. The background SST annual cycle in the tropical Pacific modulates the ENSO-associated tropical Pacific convection response, leading to a rapid enhancement of convection anomalies in winter. The enhanced convection results in a fast establishment of the large-scale PNA teleconnection during ENSO years. The dynamics of this ENSO–annual cycle interaction fills an important gap in our understanding of the seasonally modulated PNA teleconnection pattern during ENSO years.

Optical link encoding based simultaneous correction for crosstalk and nonlinearity in multi-site optical converged networks.

This paper reports a correction scheme to address the problem of modulation nonlinearity and optical switch crosstalk simultaneously for the multi-site optical converged network. Based on the optical link encoding and exclusive-or operation for the received signal, the present spectrum usage can be obtained among the confusion with interferences containing the modulated harmonic distortion and the crosstalk leakage from other sites. The proof-of-concept experiment is performed on various interferences involving the linear frequency modulated (LFM) waveform and the quadrature amplitude modulation (QAM) signal. The corrected spectrum has realized an improved signal-to-noise ratio (SNR) of over 22 dB compared to the uncorrected counterpart. Furthermore, it consistently maintains a superior SNR, surpassing the single impairment-corrected scenario by an impressive margin of at least 15.9 dB. Besides, the implementation would not introduce additional noise, making the corrected result agree well with the ideal case. Without any increase in hardware complexity, the presented scheme provides an effective technique to meet the correction challenge of large-scale and complicated optical networks with multiple optoelectronic devices.

Simultaneous dual-channel data transmission through a multimode fiber via wavefront shaping

The increasing demand for transmission capacity in fiber-optic communications makes multimode fibers (MMFs) attractive by enabling simultaneous multi-channel data transmission. However, inherent mode crosstalk among transmission channels limits its applicability. In this Letter, we propose to overcome this problem via wavefront shaping. By actively modulating the incident light with a special wavefront, not only the transmitted power for a specific channel can be enhanced but also crosstalk among different transmission channels can be mitigated. As a proof of concept, we experimentally demonstrated wavefront shaping assisted dual-channel optical communications through a single MMF. 10 Gbaud four-level pulse amplitude modulation signals were sent through both channels simultaneously, enabling a total bit rate of 40 Gbps. Both channels were analyzed with bit error rates below the hard-decision forward error correction limit, confirming the validity of the proposed scheme.

A new-generation approach to PAM-4 Based on the Fano resonance effect using a multimode interference structure

The goal of this research is to come up with a new optical structure for the generation of multilevel pulse amplitude modulation (PAM-4) signalling, which is used for optical interconnects and data center networks. The Fano effect is made with a structure made up of a 4x4 MMI coupler, feedback waveguides, and phase shifters. For the production of PAM-4, we employ the Fano effect. The new proposed approach can reduce power consumption and extend the linear region of the device transfer function compared with conventional approaches based on Mach Zehnder Interferometers (MZI) and ring resonators. We show that an extreme reduction of power consumption of 3 to 30 times, compared with the conventional structure based on MZI and ring resonators, is achieved. In addition, the proposed structure based on silicon wave guides has the advantages of extreme high bandwidth, large fabrication tolerance, and a compact footprint. The proposed structure can be applied to generate the PAM-4 based on the Fano effect with low power consumption, and it is suitable for complex systems with a lot of transceivers. The device is numerically simulated and designed using the Finite Difference Method (FDM) and Finite Difference Time Difference (FDTD). The PAM-4 structure based on silicon waveguides can be compatible with CMOS’s existing technologies.

Simplified THP and M-Log-MAP Decoder Based Faster Than Nyquist Signaling for Intra-Datacenter Interconnect

In this paper, a joint application of simplified Tomlinson-Harashima precoding (THP) and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">M</i> -log-maximum a posteriori probability ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">M</i> -log-MAP) decoder at transceivers is proposed for low complexity faster than Nyquist (FTN) 4-ary pulse amplitude modulation (PAM4) signaling. A THP with only two taps is applied at the transmitter for FTN-induced inter-symbol interference elimination and equalization-induced noise amplification issue mitigation, which effectively relieves the burden of the receiver. At the receiver, a low complexity M-log-MAP decoder is equipped for residual impairments cancellation, thus a feedback channel is not required to accurately obtain the channel state information for the transmitter. Taking advantage of this collaborative approach, the proposed scheme performs much better than applying the two schemes separately. We experimentally demonstrate the proposed scheme in 70, 75, and 80GBaud PAM4 systems with a 32-GHz brick-wall filter, corresponding to 0.914, 0.853, and 0.8 FTN compression factor, respectively. The results show that the 80GBaud PAM4 signal is successfully transmitted over 2-km single mode fiber with the bit-error-rate (BER) under the 7% hard-decision forward error correction (HD-FEC) threshold of 3.8×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−3</sup> . It is also observed that the proposed scheme shows about 0.7dB receiver sensitivity improvement compared to the error propagation-free decision feedback equalizer, namely the performance upper bound of the THP, at BER of 7% HD-FEC threshold in a 75GBaud FTN PAM4 system. According to the experimental results, the proposed scheme is a promising solution for bandwidth-starved low-cost intra-datacenter interconnect.

Detecting Massive MIMO-QAM Signal via ℓ2-Box ADMM Approach

In this letter, we develop two efficient detectors for the massive multiple-input multiple-output (MIMO) system with quadrature amplitude modulation (QAM) signal based on the ℓ2-box intersection technique and the alternating direction method of multipliers (ADMM) approach. Specifically, the first one called ADMM-1 has theoretically-guaranteed convergence under mild conditions, and the second one called ADMM-2 owns cheaper computational complexity. Moreover, all variables are solved analytically in the detection procedure. Simulation results demonstrate the effectiveness of the proposed ℓ2-box ADMM detectors in comparison with the state-of-the-art methods.

Bridging optical fiber communication and underwater wireless optical communication via third harmonic generation.

In this paper, we propose an optical module, consisting of an Erbium/Ytterbium co-doped fiber amplifier (EYDFA) and a cascaded periodically poled lithium niobate (cascaded-PPLN), to bridge the conventional telecommunication and the emerging underwater wireless optical communication (UWOC). Compared with using two discrete crystals to achieve the third harmonic generation (THG), using a cascaded crystal simplifies the optical system. Under a fundamental power of 5 W at 1550 nm, we have generated an optical power of 6.54 mW at 516 nm, corresponding to a conversion efficiency of 0.1308%. Furthermore, we added a 5-km single-mode fiber (SMF) before the EYDFA, and by adjusting the seed laser power, we successfully maintained the efficiency of the THG process and the output power of the green light. Afterwards, the nonlinearity of the THG process is analyzed, and a simplified nonlinear pre-compensation method has been proposed to tailor the 4-pulse amplitude modulation (PAM4) signals. In such case, the bit error rate (BER) of the modified PAM4 (m-PAM4) can reduce by 69.3% at a data rate of 12 Gbps. Finally, we demonstrate the practicality of our proposed system by achieving a 7-m UWOC transmission in a water tank at a data rate of 13.46 Gbps in an optical dark room. This result demonstrates the feasibility of the hybrid fiber/UWOC system, highlighting its potential for practical implementation.

Reconfigurable Generation of PAM-4 Signal Based on Fano Effect for Optical Interconnect Systems

We present a novel low-power architecture for the generation of multilevel pulse amplitude modulation (PAM-4) signal generation. A new structure of a micro-ring resonator based on a 4´4 MMI (Multimode interference) coupler is proposed to control the coupling coefficient and Fano shapes. Based on this structure, a high linearity of the transmission is created, compared with the Mach Zehnder Interferometer (MZI) conventional structure. Here, instead of using directional couplers and MZI as shown in the previous reports, in our method only two 4´4 multimode interference structures on silicon on insulator (SOI) waveguides has been used. The new design is compatible and suitable for the current CMOS fabrication technology. In this work, the special design is as follows: one of two MMI couplers is used to be a micro-ring resonator and two segmented phase shifters are used in the micro-ring resonator to generate 4 levels of the PAM-4 signal. The micro-ring resonator is controlled to work at the over-coupled region, so the Fano effect can be generated. This proposed PAM-4 architecture uses the generated Fano effect, therefore an extreme reduction in power consumption can be achieved. A large fabrication tolerance of ±500 nm and a compact footprint of 10´500 µm2 can be carried-out. The device is simulated and optimally designed using the FDTD (finite difference time domain) and EME (Eigenmode Expansion). This architecture can be useful for optical interconnects and data center network applications.&#x0D;

100Gb/s coherent optical secure communication over 1000 km based on analog-digital hybrid chaos.

In recent years, the transmission capacity of chaotic secure communications has been greatly expanded by combining coherent detection and multi-dimensional multiplexing. However, demonstrations over 1000 km fiber are yet to be further explored. In this paper, we propose a coherent optical secure transmission system based on analog-digital hybrid chaos. By introducing an analog-digital converter (ADC) and a bit extraction into the feedback loop of entropy source, the broadband analog chaos is converted into a binary digital signal. This binary digital signal is then mapped to a 65536-level pulse amplitude modulation (PAM) signal and injected into the semiconductor laser (SL) to regenerate the analog chaos, forming a closed loop. The binary digital signal from the chaos source and the encrypted signal are transmitted via wavelength division multiplexing (WDM). By using conventional digital signal processing (DSP) algorithms and neural networks for post-compensation, long-haul high-quality chaotic synchronization and high-performance secure communication are achieved. In addition, the probability density distribution of the analog chaotic signal is effectively improved by adopting the additional higher-order mapping operation in the digital part of the chaos source. The proof-of-concept experimental results show that our proposed scheme can support the secure transmission of 100 Gb/s quadrature phase shift keying (QPSK) signals over 1000 km of standard single-mode fiber (SSMF). The decrypted bit error rate (BER) reaches 9.88 × 10-4, which is well below the 7% forward error correction (FEC) threshold (BER = 3.8 × 10-3). This research provides a potential solution for high-capacity long-haul chaotic optical communications and fills the gap in secure communications based on analog-digital hybrid chaos.

Optimizing the probability mass function of complex modulated signals through adaptive channel characterization.

We propose a probability mass function (PMF) optimization scheme for quadrature amplitude modulation (QAM) signals by considering the parametric characteristic of the training sequence. The training sequence for optimization is mapped in standard Maxwell-Boltzmann (M-B) distribution, and the considered characterizing parameters incorporate either the noise variance or the error matrix of the received symbols. The proposed PMF optimization is based on independent reallocation within each constellation ring, generating new distribution with almost the same entropy and transmitted power as the original distribution. This reallocation mechanism is model-free and iterative-free with very low computational complexity. By characterizing the channel in terms of constellation performance asymmetry, PMF reallocation can be effectively implemented to supplement the existing equalization algorithm. The effectiveness of this approach is experimentally verified in a 40-km transmission system with 24 Gbaud 64-QAM signals under three different scenarios. Through PMF reallocation, we achieve generalized mutual information (GMI) improvement of ∼0.06 and throughput improvement of ∼1.5 Gbit/s before forward error correction in comparison with the standard M-B distribution. The proposed mechanism provides a solution to obtain the optimal PMF in practical communication channels, which suffer from various types of noises and distortions.

Design of multiple‐input multiple‐output radar amplitude‐bounded waveforms with desired ambiguity function based on sequential quadratic programming

AbstractThe transmit waveform with ambiguity function specifications in the range‐Doppler plane has been of great interest in traditional single antenna radar systems in recent years. This paper considers the design of waveform sets with a desired slow‐time ambiguity function for multiple‐input multiple‐output radar. Specifically, it is desirable that the ambiguity function has low sidelobes where clutter occurs, as this reduces the impact of the clutter on target detection. Instead of unimodular waveforms, the authors consider amplitude modulation signals and introduce the bound constraint on signal amplitudes into the optimisation for the consideration of transmitter efficiency. The design problem is formulated as minimising the weighted integrated sidelobes level of the ambiguity function over the range‐Doppler plane under bound constraints. The resulting problem has a highly non‐linear objective function and is constrained by bound constraints and quadratic equality (constant energy) constraints, making it difficult to solve. The authors develop an efficient algorithm based on the sequential quadratic programming technique and non‐linear conjugate gradient method to solve it. Simulation results show that the proposed algorithm is superior to the existing methods.

All-optical wavelength and format conversion of DQPSK-to-PAM4 using DLI and pump assisted NOLM

An all-optical wavelength and format conversion scheme of 20 Gbps differential quadrature phase shift keying (DQPSK)-to-4-ary pulse amplitude modulation (PAM4) signals based on the delay line interferometer (DLI) and the pump assisted nonlinear optical loop mirror (NOLM) is proposed and numerically simulated. The input DQPSK signal is converted into two star-16-ary quadrature amplitude modulation (star-16QAM) signals (namely, star-16QAM-I and star-16QAM-Q) using DLI with the time delay of 1-symbol and different linear phase shifts of π/4 and −π/4, respectively. The star-16QAM signals are converted into the on-off keying (OOK) signals (namely, OOK-I and OOK-Q) using the pump assisted NOLM based on the self-phase modulation (SPM) and the cross-phase modulation (XPM) in the highly nonlinear fiber (HNLF). The two OOK signals can be aggregated into different types of PAM4 signals by adjusting their power ratio (PR) and relative phase shift (RPS) flexibly. Error vector magnitude (EVM) and bit error rate (BER) for the input and output optical signals are calculated to verify the scheme performance. Compared to the DQPSK signal with an input optical signal-to-noise ratio (OSNR) of 30 dB, there are about 2.5 dB penalty of receiver OSNR for the converted OOK-I and OOK-Q signals. For the corresponding aggregated equidistant PAM4 and equiamplitude PAM4 signals, they have about 6.3 dB and 12.1 dB penalty of receiver OSNR. The proposed scheme of DQPSK-to-PAM4 can be deployed at the all-optical gateway to bridge the long-hual and short-reach optical networks.

Kramers–Kronig Transmission with a Crosstalk-Dependent Step Multiple-Input Multiple-Output Volterra Equalizer in a Seven-Core Fiber

In this paper, we experimentally demonstrate a net bit rate of 261.7 Gbit/s in a seven-core transmission system with a Kramers–Kronig (KK) receiver. The 10 GBaud 16-level quadrature amplitude modulation (QAM) signal is transmitted over a 2.5 km seven-core fiber, and the relationship between carrier-to-signal power ratio, signal power, frequency spacing, and optical power is analyzed. Moreover, a multiple-input multiple-output (MIMO) Volterra equalization algorithm with crosstalk-dependent steps is proposed to compensate for inter-core crosstalk and impairments induced by other devices. Compared to the single-input single-output (SISO) Volterra equalizer, the CSPR can be reduced by 1.3 dB, and the received power gain can reach up to 0.7 dB.

Effects of periodic parametric damping and amplitude-modulated signal on vibrational resonance and torus-doubling bifurcations occurrence in an asymmetric mixed Rayleigh-Liénard oscillator

This research paper examines the effects of periodic parametric damping and amplitude-modulated signal on vibrational resonance and the occurrence of torus-doubling bifurcations in an asymmetric mixed Rayleigh-Liénard oscillator. The method of direct separation of the slow and fast motions is used to derive the approximate theoretical expression of response amplitude at the low frequency. The obtained results show that the presence of periodic parametric damping induces in the system multiple resonance peaks when the low frequency is varied. Moreover, the increase of carrier amplitude modulated increases or decreases the maximum amplitude value in certain range of the low frequency. However, when the periodic parametric damping coefficient is varied, one resonance peak occurs and the maximum amplitude value increases when the carrier amplitude modulated increases. The theoretical and direct numerical predictions have shown a fairly satisfactory agreement. On the other hand, the global dynamical changes of the system are numerically examined in context of vibrational resonance. It is found that, the system displays many torus attractors of different topologies, torus-doubling bifurcations, reverse torus-doubling bifurcations and torus-chaos. These observations are illustrated by plotting the phase portraits and their corresponding Poincaré maps.

Deep-Learning-Enabled Direct Detection With Reduced Computational Complexity and High Electrical-Spectral-Efficiency

Complex-valued double-sideband (CV-DSB) direct detection (DD) is a promising solution for high capacity and cost-sensitive data center interconnects, since it can reconstruct the optical field as a homodyne coherent receiver while does not require a costly local oscillator laser. In a carrier-assisted CV-DSB DD system, the carrier occupies a large proportion of the total optical signal power but bears no information. Reducing the carrier to signal power ratio (CSPR) can improve the information-bearing signal power and thus maximize the achievable system performance. Recently, we have proposed and demonstrated a deep-learning-enabled DD (DLEDD) scheme to reconstruct the full-field of the CV-DSB signal. In the DLEDD scheme, the optical CV-DSB signal was detected by a dispersion-diversity receiver and then recovered by a deep convolutional neural network (CNN). Nevertheless, the computational complexity of the deep CNN is the main obstacle to the application of the DLEDD scheme. In this paper, we demonstrate a 50-GBaud CV-DSB 32-ary quadrature amplitude modulation (32-QAM) signal transmission over 80-km single-mode fiber with ∼64% computational-budget reduction in the field reconstruction. This is achieved by using 1×1 convolutions to attain a sparse dimensionality (in particular the number of channels) of the deep CNN. To the best of our knowledge, we achieve the highest electrical spectral efficiency of 7.07 b/s/Hz per polarization per wavelength for a CV-DSB DD receiver without requiring a sharp-roll-off optical filter.