Quadrature Amplitude Modulation Research Articles

Wifi 7: Advancements, Applications and Future Prospects

The goal of Wi-Fi 7, a major advancement in wireless networking technology, is to satisfy the increasing demand for faster data speeds, reduced latency, and more spectrum economy. Building on the success of Wi-Fi 6 and 6E. this next generation offers previously unheard-of speeds of up to 30 Gbps and improved network stability with innovations like 320 MHz channel width, 4096-QAM (Quadrature Amplitude Modulation), and Multi-Link Operation (MLO). Virtual/augmented reality (VR/AR). high-definition media streaming, sophisticated loT ecosystems, and industrial automation arc just a few of the many uses that Wi-Fi 7 is anticipated to enable. Wi-Fi 7 is expected to serve new use cases that require dependable, fast wireless connections, such smart cities, real-time telemedicine, and driverless cars, thanks to its extremely low latency and smooth multi-connection management

Method for determining the effect of destabilizing factors of digital filters on the multicriteria synthesis of radio communications of aviation robotic devices

The purpose of the research is development of a method for determining the influence of destabilizing factors, such as the unevenness of the amplitude-frequency response (AFC) and the nonlinearity of the phase-frequency response (FFC), in non-recursive digital frequency selection filters on the target function of multicriteria structural-parametric synthesis of radio communications from the payload of aviation robotic devices.Methods. In conducting scientific research, probability theory, mathematical statistics, statistical radio engineering and computational mathematics were used. The study obtained mathematical expressions of the dependence of the probability of error per bit (BER) on the average signal-to-noise ratio when signals pass through symmetrical non-recursive digital filters with quadrature amplitude modulation with a positivity of no more than 4096, signal constellation irregularities of no more than 5, which are the basis for the energy balance of radio lines with aviation robotic devices. The expressions obtained are one of the "foundations" for the implementation of a multi-criteria synthesis of radio systems adaptive to a cognitively formed flight task. In this paper, all the results of the probability of reliability of the received data by means of communication are reflected for the case of rigid decision-making (Gray coding).Results. In the course of the conducted research: 1) a mathematical model of the structural-parametric synthesis of radio communications with aviation robotic devices is demonstrated, which is based on the criteria for minimizing: electronic computing resources with a given noise immunity; radiation outside the operating frequency band; peak factor signals; the effects of narrowband, broadband and structural interference in the radio channel at a given bandwidth; the use of structural and functional nodes specific to the existing information and communication environment; 2) the analytical dependence of the influence of the parameters of one of several structural and functional nodes - digital filters of frequency selection, on the criteria for the synthesis of communication means has been revealed. The paper considers the most common approximating functions - Kaiser, Tukey, Barlett-Khan, Chebyshev, and also shows the influence of the filter order on the equivalent of energy loss in information communication lines of aviation robotic devices.Conclusion. The scientific article presents a method for determining the effect of the uneven frequency response of a symmetrical non-recursive digital filter in devices for receiving and processing radio signals of multicriteria means of communication with the payload of aviation robotic devices. The proposed approach increases the reliability of determining the values of criteria for minimizing electronic computing resources for a given noise immunity, radiation outside the operating frequency band, as well as the use of structural and functional nodes characteristic of the existing information and communication environment.

Simplified bit-class probabilistic shaping strategy based on PDM systems.

This study aims to present a simplified bit-class probabilistic shaping (PS) strategy based on power domain multiplexing (PDM) systems. In this scheme, we employ bit-weighted distribution matching (BWDM) to achieve PS. By ingeniously applying the process of signal superposition, the low-complexity bit-class PS scheme requires encoding of only a small number of bits in the low-power two quadrature phase-shift keying (QPSK) signal, enhancing the quality of the transmitted signal with simple operations. At the receiver, to ensure the transmission performance of the system while minimizing computational complexity and enhancing system operational efficiency, we implemented the region decision method for demodulation. The proposed scheme was experimentally validated on a 2 km 7-core fiber, achieving accurate transmission of signals at a net rate of 103.6 Gb/s. The experimental results indicate that, when compared to the uniform 16-quadrature amplitude modulation (16QAM) signal and the PDM-orthogonal frequency division multiplexing (OFDM) signal without PS, the receiving sensitivity of the PS-16QAM signal in our scheme can gain 0.4 dB and 0.33 dB at a bit error rate (BER) of 3.8 × 10-3 under the same net rate.

Enhanced Carrier Phase Recovery Using Dual Pilot Tones in Faster-than-Nyquist Optical Transmission Systems

Compared with high spectrum efficiency faster-than-Nyquist (FTN) backbone network, an enhanced carrier phase recovery based on dual pilot tones is more sensitive to capital cost in FTN metropolitan areas as well as inter-datacenter optical networks. The use of distributed feedback (DFB) lasers is a way to effectively reduce the cost. However, under high symbol rate FTN systems, equalization-enhanced phase noise (EEPN) induced by a DFB laser with large linewidth will significantly deteriorate the system performance. What is worse, in FTN systems, tight filtering introduces inter-symbol interference so severe that the carrier phase estimation (CPE) algorithm of the FTN systems is more sensitive to EEPN, thus it will lead to a more serious cycle slip problem. In this paper, an enhanced carrier phase recovery based on dual pilot tones is proposed to mitigate EEPN and suppress cycle slip, in which the chromatic dispersion (CD)-aware Tx and LO laser phase noise is estimated, respectively. Offline experiments results under 40 Gbaud polarization multiplexing (PM) 16-quadrature amplitude modulation (QAM) FTN wavelength division multiplexing (FTN-WDM) systems at 0.9 acceleration factor, 5 MHz laser linewidth, and 500 km transmission demonstrate that the proposed algorithm could bring about 0.65 dB improvement of the required SNR for the normalized generalized mutual information of 0.9 compared with the training sequence-based cycle slip suppression carrier phase estimation (TS-CSS) algorithm.

OFDM system based on parametric DFT transform

This study introduces a specific type of orthogonal frequency division multiplexing (OFDM) system that relies on the parametric discrete Fourier transform (DFT-alpha), where alpha is a parameter randomly selected within the range [-2pi, 0]. We investigate the performance of the proposed system across various channel types and modulation formats, including binary phase shift keying (BPSK), 16 quadratic amplitude modulation (QAM), analyzing aspects such as bit-error rate (BER), peak-to-average power ratio (PAPR), and computational complexity. This work considers the most interesting special case of the one-parameter DFT, which is the DFT-π/6 . The simulated results confirm the suggested OFDM system’s ability to minimize the computational complexity of the conventional OFDM system, standing as the primary contribution of the current study, while maintaining the performance identical. Therefore, the parametric DFT-OFDM system would be a good alternative to the classical DFT-OFDM. The findings suggest that parametric DFT based OFDM holds significant potential for high-speed optical wireless communication systems.

1.06 Tbit/s space division multiplexing self-homodyne coherent transmission with high spectral efficiency probabilistic shaping multidimensional modulation

We propose a probabilistic shaping multidimensional (MD) modulation format for self-homodyne coherent transmission systems. The redundancy of the MD signal is separated and transmitted together with the optical pilot tone (PT). The 4D/8D/12D modulation is constructed at the transmitter based on the amplitude translation (AT)-set partitioning (SP) principle and the probabilistic amplitude shaping (PAS) structure. Moreover, the hard-decision (HD) and soft-decision (SD) decoders for MD signals are introduced. We implement 20 GBaud 4D/8D/12D probabilistic shaping (PS) 16384-level quadrature amplitude modulation (QAM) transmission over 22.5 km uncoupled multicore fiber to analyze the performance. The experimental results show that it is possible for the MD signal to provide spectral efficiency (SE) gain up to 3.31 bit/s/Hz/4D-sym. The maximum SE transmitted is up to 57.29 bit/s/Hz, i.e., 17.5 bit/s/Hz/4D-sym, with a bit rate of 1.06 Tbit/s.

Photonics-assisted self-interference cancellation for in-band full-duplex integrated sensing and communication transceiver

In-band full-duplex (IBFD) operation is essential for both sensing-centric and communication-centric integrated sensing and communications (ISAC) systems. Both types require the monostatic transceiver to overcome the technical challenge of self-interference (SI). To address this challenge, a photonics-assisted self-interference cancellation (SIC) scheme for an IBFD ISAC transceiver is proposed and experimentally demonstrated. By utilizing wavelength division multiplexing, the SI is cancelled by a cancellation reference with matched amplitude and time delay, using two counter-biased Mach-Zehnder modulators. In proof-of-concept experiments, the proposed IBFD ISAC transceiver is tested using a 10 GHz quadrature amplitude modulation (QAM) constant envelope linear frequency modulation orthogonal frequency division multiplexing (CE-LFM-OFDM) ISAC signal with a carrier frequency and a bandwidth of 10 GHz and 2 GHz, respectively. Experimental results show that cancellation depths of 35.29 dB and 32.59 dB are achieved with bandwidths of 1 GHz and 2 GHz, respectively, in the communication receiver. The corresponding weak signal of interest is successfully recovered after effective SIC in the wireless link. The ranging and imaging functions are also experimentally verified. The experimental results show that the cancellation depth of the SI after de-chirping is 23.6 dB when the center frequency and bandwidth of the CE-LFM-OFDM RF signal are 10 GHz and 2 GHz, respectively. A dynamic range increase of 23.84 dB is achieved in imaging function. The corresponding radar ranging resolution of 10 cm is also achieved for radar function. The proposed scheme cancels the SI in both communication and radar receivers, demonstrating excellent performance in the IBFD ISAC transceiver system.

SSBI counteraction technology in a single photodetector-based direct detection system receiving an independent dual-single sideband signal

To further meet the large capacity, high spectrum efficiency (SE), reduce the signal-signal beat interference (SSBI) of the independent dual single sideband (ISB) system and the complexity of the receiver, we propose an iterative signal-signal beat interference counteraction (ISSBIC) algorithm to suppress SSBI. The 16-Gbps left sideband and the 16-Gbps right sideband signals in the ISB system are quadrature phase-shift keying (QPSK) modulated. After standard single-mode fiber (SSMF) transmission, the LSB and RSB signals are synthesized to a 16-quadrature amplitude modulation (QAM) signal after conversion through the photodetector (PD) square law. The simulation results show that the ISSBIC with just 2 iterations is superior to Kramers–Kronig (KK) receiver in processing the system error bit. In the meantime, the ISSBIC requires a sampling rate of 20GSa/s, whereas KK requires 40GSa/s. Moreover, the proposed ISSBIC algorithm has a simpler complexity. According to the simulation results, the suggested ISSBIC receiver can lower the ADC requirements and system costs, which opens up a wide range of applications in multiplex and higher SE transmission systems.

Utilization of Optical OFDM Modulation on Blue LED VLC Datacom Without Equalization for 4 m Wireless Link

To achieve higher visible light communication (VLC) traffic capacity, using the wide bandwidth light-emitting diode (LED) and spectral efficiency modulation signal, is currently the most commonly used method. In this demonstration, we apply the orthogonal frequency division multiplexing quadrature amplitude modulation (OFDM-QAM) with bit- and power-loading algorithm on single blue LED to achieve >1 Gbit/s VLC capacity, when a 400 MHz bandwidth avalanche photodiode (APD)-based receiver (Rx) is exploited for decoding. Here, the higher sensitivity APD can be applied to compensate for the wireless VLC link length in the proposed LED VLC system, and due to the lower LED illumination (255 to 40 lux), is used for the indoor access network after passing the wireless link length of 1 to 4 m. As a result, using single blue LED can achieve 0.962 to 1.057 Gbit/s OFDM rate with available 400 MHz bandwidth APD in poorly illuminated condition indoors without applying analogy equalization.

Cognitive learning enabled agile optical network

Nonlinear equalization (NLE) is essential for guaranteeing the performance of an optical network (ON). Effective NLE implementation relies on key parameters of the transmission link, including the modulation format (MF) and the launch power. As ONs become more agile, the parameters of fiber optical transmission need to be adaptive and relevant to the routing condition. Therefore, successful NLE implementation relies on the realization of transmission awareness (TA). Although machine learning-enabled optical performance monitoring (OPM) has been extensively investigated in the past few years, current NLE algorithms cannot autonomously perceive transmission parameters. Furthermore, current TA implementation still needs human intervention to guide the NLE. In addition, existing ML-based OPM and NLE cannot be trained autonomously, leading to the incapability of environmental change and mislabeling. Here, we propose cognitive learning (CL) for TA-guided NLE in agile ONs. We perform an experiment involving 32 Gbaud polarization-division-multiplexed (PDM)-quadrature phase shift keying (QPSK)/16-quadrature amplitude modulation (QAM) transmission over 1500 km of standard single-mode fiber (SSMF) with a variable launch power from 0 to 3 dBm. When a deep neural network (DNN) with amplitude histograms (AHs) as inputs and one step per span-learned digital back-propagation (1stps-LDBP) are developed, the CL simultaneously enables both TA and NLE, with the capability of self-learning, mislabeling resistance, and dynamic adaptation. The proof-of-concept experimental results indicate that both the accuracy of TA and the Q-factor of PDM-16QAM can be improved by 34.8% and 0.84 dB, respectively, when the launch power is 3 dBm. Moreover, the accuracy of TA is enhanced by 35.3%, even when the used data has 30% mislabeling. Therefore, the CL framework can be customized to satisfy various NLE implementations, thereby supporting the adaptive transmission of agile ONs.

Research on the Progress of Modulation Technology and Data Transmission Technology in Underwater Wireless Optical Communication

Recently, as an efficient data transmission method, underwater wireless optical communication has become one of the key research topics in the fields of military communication and underwater surveillance. Modulation technology and technology in the transmission process play a key role in the UWOC system, which directly affects the performance, accuracy and safety of the system. The advanced modulation techniques from Intensity Modulation (IM), Pulse Modulation, Quadrature Amplitude Modulation (QAM), and Quadrature Phase Shift Keying (QPSK) to the combination of multiple modulation techniques, as well as the development process of modulation technology in optical encryption, are summarized in this paper. In terms of data transmission technology, the technological progress process from simplex to full-duplex communication is summarized. Finally, a reference solution is proposed to solve the challenges in realizing the underwater communication goals of long-distance, high-speed, low-bit error rate, and large-capacity underwater communication at the same time, and future development is prospected.

Simultaneous generation of dual 16-QAM-modulated millimeter-wave signals enabled by precoding-based optical I/Q modulation and single photodetector detection

Integration of quadrature-amplitude-modulation (QAM) modulation and millimeter-wave (mm-wave) technology ensures a concise enhancement of transmission capacity and peak data rates in radio-over-fiber (RoF) systems. Nevertheless, with the continuous development of new-generation mobile applications, higher demands on access flexibility have also been formulated. We propose a novel, to the best of our knowledge, dual 16-QAM-modulated mm-wave signal generation scheme for the simultaneous generation and transmission of two independent 16-QAM signals with different carrier frequencies, enhancing the channel capacity, spectrum efficiency, and access flexibility of the RoF systems. In our proposed scheme, the generation of the optical dual 16-QAM-modulated mm-wave signals is implemented by a precoding-based optical in-phase/quadrature (I/Q) modulator operating at optical carrier suppression (OCS) mode, and their detection is implemented by a single photodetector (PD). At the transmitter side, two independent driving QAM vector radio-frequency (RF) signals with precoding, generated via digital signal process (DSP), are fed into two parallel Mach–Zehnder modulators (MZMs) of an I/Q modulator to implement OCS modulation. The I/Q modulator generates optical carriers carrying both information from different QAM signals simultaneously. After square-law detection in a single PD, we generate the desired dual 16-QAM-modulated mm-wave signals with photonic frequency-doubling and recover the original 16-QAM signals without information distortion. Based on our proposed scheme, we experimentally demonstrate the simultaneous generation and transmission of 2-Gbaud dual 16-QAM-modulated mm-wave signals with carrier frequencies of 26 GHz and 40 GHz, respectively. After transmission over 10-km single-mode fiber (SMF) link and 1.2-m wireless link, the dual 16-QAM signals can be successfully separated and demodulated by a common DSP. Bit-error ratios (BERs) of both recovered 16-QAM signals can reach the hard-decision forward-error-correction (HD-FEC) threshold of 3.8×10−3. Compared with the existing schemes, our scheme only requires one-half of the driving frequency to generate dual 16-QAM-modulated mm-wave signals with the same carrier frequency. The result indicates that our proposed scheme can lower bandwidth requirements for optoelectronics devices, along with implementing better spectral efficiency and receiver sensitivity, which is more applicable to the demands for increased system capacity and multi-frequency access flexibility in future systems.

Bi-directional SMF-NDF-optical/5G NR wireless converged systems

This study presents the transmission of fifth-generation (5G) new radio (NR) signals over bi-directional single-mode fiber (SMF)-negative dispersion fiber (NDF)-optical/5G NR wireless converged systems, using two cascaded reflective semiconductor optical amplifiers (RSOAs). Downstream transmission of 5G NR 16-quadrature amplitude modulation (QAM) signals achieved an aggregate net bit rate of 228.037 Gb/s, comprising 59.813, 74.766, and 93.458 Gb/s at 150, 250, and 325 GHz, respectively. The system achieved a low bit error rate (BER) and clear constellation patterns. However, systems without NDF exceed the forward error correction 7% threshold, indicating the importance of NDF in compensating for fiber dispersion. Moreover, for upstream transmission, two cascaded RSOAs are used to transmit 5G 16-QAM-orthogonal frequency division multiplexing signals, achieving a total data rate of 40 Gb/s. The use of two cascaded RSOAs in the system significantly improved upstream performance, resulting in low BERs and clear constellation patterns. This system not only achieved high data rates but also extended transmission coverage to support the deployment of advanced 5G NR applications.

An efficient non-binary QC-LDPC coded modulation scheme for long-haul optical systems

Abstract Coded modulation (CM), which combines channel codes with high-dimensional modulation schemes, is an attractive technique to improve the spectral efficiency in high-speed optical transmission systems. Non-binary low-density parity check (NB LDPC) codes can provide larger coding gains with smaller codeword lengths compared to their binary counterpart, in addition to reducing the latency of the system. The majority of works based on NB LDPC CM focus on bit-interleaved CM (BICM) and the widely used additive white Gaussian noise (AWGN) channel model. However, the Gaussian channel model is not a realistic model for long-haul intensity-modulated direct-detection (IM/DD) optical systems using erbium-doped fiber amplifiers. In this paper, it is mathematically proved that noise in the received signals after photodetection can be more accurately represented using chi-squared distribution. The efficiency of CM depends on the mapping between coded symbols and the constellation signal points of the modulation scheme. Hence, a symbol interleaved CM with subcarrier modulation for NB LDPC codes based on the proposed channel model is presented in this paper to improve the bit-error rate (BER) performance. The simulation results show that the proposed CM for NB LDPC codes with M-ary quadrature amplitude modulation schemes provides better performance than BICM. The analysis of the error performance of the proposed system gives a coding gain of 1 dB at a BER of 10−7 compared to that of the AWGN channel model. The performance improvement of the system is also evaluated in terms of spectral efficiency and link distance.

Enhanced Performance Analysis of 120 Gbps Single‐Channel IQ Modulation Based PDM‐FSO Transmission System Using 64‐QAM Signals

ABSTRACTThe ever‐augmenting demand of data channel‐bandwidth by the end users has resulted in the exploration of new transmission techniques for wireless transmission networks. In this work, we have demonstrated the modeling of a single‐channel free space optics (FSO) transmission system by employing polarization‐division‐multiplexing (PDM) technique. Further, in‐phase‐quadrature modulation (IQM) has been used to increase the transmission efficiency of the system. To decrease the baud‐rate of the system, we have proposed the use of 64‐level quadrature amplitude modulation (QAM) signals. The net transmission rate of the system is 120 Gbps with a baud‐rate of 10 Gbps. Furthermore, the overcome the signal degradation of the 120 Gbps signal propagating through atmospheric channel, we have reported the use of advanced digital signal processing (DSP) algorithms. The system's performance is investigated for adverse external climate weather conditions and the results reported show reliable 120 Gbps data transmission along range between 870 m and 16.25 km with good performance of BER and EVM 7.5%.

Review on Preamble-Based Channel Estimation Method for FBMC/OQAM Toward 6G: Advantages, Challenges and Future Works

Filter bank multicarrier/offset quadrature amplitude modulation (FBMC/OQAM) is a multicarrier modulation that is expected to replace orthogonal frequency division multiplexing (OFDM) in future sixth-generation (6G) networks. FBMC/OQAM has high spectrum efficiency, cyclic prefix (CP)-free transmission, decreased out-of-band emission (OOBE), and asynchronous environment robustness. However, the orthogonality criteria of FBMC/OQAM are only in the real field. Therefore, imaginary components of complex-valued OQAM symbols cause imaginary interferences among subcarriers, affecting channel estimation (CE) processing operations. Channel estimation is a critical component of wireless communication systems. Channel estimate allows the receiver to approximate channel impulse response (CIR) to determine the impacts of the communication channel on the sent symbols. So, an accurate channel estimate is critical in FBMC/OQAM. In this review, we focus on the Preamble-based method, one of the basic methods for channel estimation in FBMC. Three preamble-based approaches have been studied: the interference approximation method (IAM), the interference cancellation method (ICM), and pairs of pilots (POP) using a single antenna and multiple input multiple outputs (MIMO). Compare them regarding bit error rate (BER) and mean square error. Also, it compares different interference approximation methods in terms of bit error rate (BER), magnitude, and peak average power ratio (PAPR). The review found the superiority of M-IAM and NPS in spectrum efficiency and PAPR. Future work that can help the researcher in this field.

Design of an Integrated System for Spaceborne SAR Imaging and Data Transmission.

In response to the conflicting demands between real-time satellite communication and high-resolution synthetic aperture radar (SAR) imaging, we propose a method that aligns the data transmission rate with the imaging data volume. This approach balances SAR performance with the requirements for real-time data transmission. To meet the need for mobile user terminals to access real-time SAR imagery data of their surroundings without depending on large traditional ground data transmission stations, we developed an application system based on filter bank multicarrier offset quadrature amplitude modulation (FBMC-OQAM). To address the interference problem with SAR signals' transmission and reception, we developed a signal sequence based on spaceborne SAR echo and data transmission and reception. This system enables SAR and data transmission signals to share the same frequency band, radio frequency transmission system, and antenna, creating an integrated sensing and communication system. Simulation experiments showed that, compared to the equal power allocation scheme for subcarriers, the echo image signal-to-noise ratio (SNR) improved by 2.79 dB and the data transmission rate increased by 24.075 Mbps.

Study of high-order non-equal probability QAM for visible light communication systems.

In this Letter, we propose and experimentally demonstrate a high-order non-equal probability quadrature amplitude modulation (NEP-QAM) scheme for visible light communication (VLC) systems, where NEP-72QAM is considered as an example. Nonlinear coding is introduced to generate the NEP-18QAM signal in the first quadrant, which is then jointly mapped with the other two bits to obtain the four-quadrant symmetric NEP-72QAM signal. Moreover, a bit-to-symbol labeling scheme is proposed to achieve thorough Gray mapping. The experimental results show that the NEP-72QAM scheme achieves better performance than the traditional 64QAM scheme regardless of whether the light-emitting diode (LED) operates in the linear or nonlinear range. Compared with the probabilistically shaped 72QAM scheme, the available range of the driving peak-to-peak voltage of the NEP-72QAM scheme is only reduced by 20 mV when 0.92 is used as the normalized generalized mutual information threshold, but the complexity is much lower.

Digital pre-equalization for performance improvement in coherent PON

As high-speed optical access networks continue to evolve, reducing the computational complexity at the optical network unit (ONU) side remains a significant challenge in coherent passive optical network (PON). This paper presents a pre-equalization scheme that integrates digital pre-distortion (DPD) and pre-emphasis techniques in 200 Gb/s coherent PON. The focus is on three modulation formats: 50 Gbaud polarization multiplexing-quadrature phase shift keying (PM-QPSK), 50 Gbaud Alamouti-coded polarization multiplexing-16 quadrature amplitude modulation (PM-16QAM), and 25 Gbaud PM-16QAM, using intradyne or heterodyne detection schemes. Through comprehensive numerical simulations and experimental evaluations, we demonstrate significant improvements in receiver sensitivity and power budget in 200 Gb/s coherent PON. When the number of digital filtering taps is small, the proposed scheme achieves power budget enhancements of 3 dB for 50 Gbaud PM-QPSK, 7 dB for 50 Gbaud Alamouti-coded PM-16QAM, and 2.1 dB for 25 Gbaud PM-16QAM in the downlink. These findings highlight the potential of pre-equalization techniques in enhancing the performance of next-generation coherent PON with low computational complexity at the ONU side.

Optimization of probabilistic and geometrical shaping in RoF system based on overlapping labels

We used a hybrid probabilistic geometric shaping scheme that uses a probabilistic shaping method with labels and a pairwise optimization (PO) algorithm to transmit signals in a 2 × 2 MIMO Photon-assisted millimeter wave (MMW) radio-over-fiber (RoF) system in the D-band. This scheme has low complexity and a simple recovery method. This scheme optimizes 16-ary quadrature amplitude modulation (16QAM) to probabilistically shaped 9-ary quadrature amplitude modulation (PS-9QAM) by adding labels, and optimizes it to hybrid probabilistically and geometrically shaped 9-ary quadrature amplitude modulation (PGS-9QAM) by geometric shaping using the PO algorithm. The experimental results prove the optimization effect of this scheme. Under the bit error rate threshold of 0.0038, when the net bit rate is the same, compared with 16QAM, PS-9QAM and PGS-9QAM, the optical power at the transmitter can be reduced by 0.8 dB and 1.45 dB respectively. When the transmission power is the same, compared with 16QAM, the net rates of PS-9QAM and PGS-9QAM can be increased by 7.5Gbit/s and 9Gbit/s respectively.