[1] Sugiyama H, Nosu K. MPPM: a method for improving the band-utilization efficiency in optical PPM[J]. Journal of Lightwave Technology, 7, 465-472(1989).

[2] Nguyen T T, Lampe L. MPPM constellation selection for free-space optical communications[J]. IEEE Transactions on Communications, 60, 632-636(2012).

[3] Yang Z J, Fang Y, Zhang G H et al. Design and optimization of protograph LDPC-coded multipulse PPM systems over Poisson channels[J]. IEEE Transactions on Vehicular Technology, 71, 9586-9601(2022).

[4] Escribano F J, Wagemakers A. Performance analysis of QAM-MPPM in turbulence-free FSO channels: accurate derivations and practical approximations[J]. IEEE Systems Journal, 15, 1753-1763(2021).

[5] Khallaf H S, Shalaby H M H, Garrido-Balsells J M et al. Performance analysis of a hybrid QAM-MPPM technique over turbulence-free and gamma-gamma free-space optical channels[J]. Journal of Optical Communications and Networking, 9, 161-171(2017).

[6] Lü L, Fang Y, Dai L et al. Asymmetric dual-mode constellation and protograph LDPC code design for generalized spatial MPPM systems[J]. IEEE Transactions on Communications, 71, 3165-3177(2023).

[7] Sun Z L, Tang D, Zuo W et al. Triple-convex probabilistic constellation shaping PAM8 in IM/DD system[J]. IEEE Photonics Technology Letters, 35, 846-849(2023).

[8] Puzko D, Batov Y, Gelgor A et al. QAM constellations with fractional entropy to gain in margin maximization for frequency selective channels[J]. IEEE Communications Letters, 27, 1457-1461(2023).

[9] Zhang Q L, Shu C. Optimum constellation size for probabilistically shaped signals in the presence of laser phase noise[J]. Journal of Lightwave Technology, 40, 947-953(2022).

[10] Ding J J, Zhang J, Wei Y R et al. Comparison of geometrically shaped 32-QAM and probabilistically shaped 32-QAM in a bandwidth-limited IM-DD system[J]. Journal of Lightwave Technology, 38, 4352-4358(2020).

[11] Hu X, Zhao L, Yu J J. Probabiliy shaping orthogonal frequency division multiplexing optical signal transmission system based on wavelength conversion[J]. Laser & Optoelectronics Progress, 60, 1906001(2023).

[12] Chen D, Ai F E, Wang R et al. 16QAM adaptive probability shaping under combined influence of turbulence and phase noise[J]. Acta Optica Sinica, 43, 2406004(2023).

[13] Jia X S, Li Y, Luo M et al. Many-to-one mapping based truncated probabilistic shaped 64-QAM for metro transmissions enabled by polar code[J]. Journal of Lightwave Technology, 41, 6700-6709(2023).

[14] Cao Z Q, Chen Y F, Zhao X et al. Probabilistic shaping 44QAM based on many-to-one mapping in DMT-WDM-PON[J]. IEEE Photonics Technology Letters, 32, 639-642(2020).

[15] Moision B, Hamkins J. Coded modulation for the deep-space optical channel: serially concatenated pulse-position modulation[J]. Interplanetary Network Progress Report, 42, 1-25(2005).

[16] Wu X W, Yang L, Zhan Y Y et al. Photocount characteristics of SNSPD for PPM signals in deep-space laser communication (invited)[J]. Laser & Optoelectronics Progress, 61, 0706015(2024).

[17] Leng J F, Hao S Q, Lü X G et al. Study on bit-symbol mapping method of MPPM and system performance based on low density parity check codes[J]. Acta Optica Sinica, 32, 0406001(2012).

[18] He H L, Chen Y F, Xiao Q H et al. LDPC-coded probabilistic shaping PAM4 based on many-to-one mapping in WDM-PON[J]. Journal of Lightwave Technology, 38, 3918-3925(2020).

[19] Pan C P, Kschischang F R. Probabilistic 16-QAM shaping in WDM systems[J]. Journal of Lightwave Technology, 34, 4285-4292(2016).

[20] Qin L, Du Y X, Ke X Z et al. Implementation of coding and decoding system for three-pulse MPPM in atmosphere laser communication[J]. Semiconductor Optoelectronics, 29, 403-406, 433(2008).

[21] Wang X, Du J. A normalization-free information updating algorithm for MAP decoder[J]. Telecommunication Engineering, 61, 1238-1242(2021).

[22] Hu Y P, Zhang T Q, Bai Y L et al. A blind recognition algorithm for the component encoder of punctured turbo code[J]. Journal of Signal Processing, 37, 2207-2215(2021).