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Abstract In the context of certain specific digital communication systems, where there are limitations such as spectral resources and energy availability, continuous phase modulation (CPM) emerges as an appealing choice among various modulation methods. Among CPM signals, multi‐h CPM is particularly noteworthy for its ability to address these constraints within the realm of single‐carrier and constant‐envelope waveforms. At the physical layer, the design of a multi‐h CPM receiver necessitates the efficient implementation of timing and frequency synchronization algorithm within a high dynamic environment. So this paper presents an innovative approach for achieving timing and frequency synchronization. To rectify timing offset and mitigate the adverse effects of noise in received signals, a re‐configurable local filter generation method is integrated into the timing synchronization algorithm. Simultaneously, an enhanced least mean square adaptive filter algorithm is applied to address frequency synchronization. A comprehensive series of simulations rigorously evaluates the outcomes of proposed novel synchronization methodology. These analyses demonstrate a notable proximity between the synchronization errors of proposed algorithm in this paper and the performance benchmark set by the modified Cramer–Rao bound. The proposed synchronization technology also exhibits the capability to substantially reduce the bit error rate, thereby effectively enhancing demodulation performance in multi‐h CPM receivers.

Satellite optical communication networks have become a promising core network structure, surpassing 5G and 6G, and are expected to realize seamless connections between terrestrial and non-terrestrial networks. Constructing an optical satellite network that can achieve various link schemes and enable bidirectional communication with multiple optical satellites at a low cost (including low power consumption, low weight, and low space occupation for each satellite) poses a technical challenge. In this paper, we propose and establish a multi-format/rate-tunable integrated laser communications hardware platform that can switch between different links by controlling the modulation format and rate. The platform supports OOK, QPSK, and BPSK modulation with rates ranging from 0.625 to 10 Gbps. Experimental demonstration of bidirectional communication is conducted over a free-space optical link. At a distance of 510 meters, sensitivity tests are conducted for signals with various modulation formats and rates. The receiving sensitivity at the 3.8e-3 FEC threshold is −46 dBm for 10 Gbps PDM-QPSK signal, and is −58 dBm for 625 Mbps BPSK signal. Results show excellent signal sensitivity across different formats and rates. Additionally, the platform is capable of performing ranging while communicating with a minimal ranging error of 2.9% of the width of a code word.