Regional carbon efficiency (CE) improvement is critical to China’s “taking concerted efforts to achieve ecological protection” strategy in the Yangtze River Economic Belt (YREB) and their program to build a leading demonstration belt for ecological civilization. This study applied the super efficiency slacks-based measure to calculate the regional differences and evolution characteristics of the YREB’s CE from the year of 2006 to 2017. It also constructed a coupling evaluation model to empirically analyze the interactions between CE and technology absorptive capacity (TAC). The results showed that (1) the CE for all YREB provinces followed a “U-shaped” trend. TAC generally increased and incrementally decreased in the sequence of the upper stream, middle stream, and downstream. The gap among the downstream, upper stream, and middle stream increased; (2) coupling between the CE and TAC for the YREB provinces can be characterized as a relatively stable medium to low coupling degree and medium-to-high coordination degree. To improve coupling and achieve balanced, sustainable development in the YREB, this study proposes several measures, including promoting balanced, high-quality economic development, building the YREB talent pool, appropriately guiding foreign capital flows, implementing the strategy of driving economic development through innovation, and launching the network for coordinated technological innovation in YREB.

In this paper, we investigate the expected outage probability and expected throughput of a multi‐user multiple‐input multiple‐output (MU‐MIMO) transmission in mobile ad hoc networks (MANET) in the presence of co‐channel interference and unpredictable inter‐beam interference. In order to achieve multi‐user diversity gain, the receiving nodes are required to report measured channel information to the transmitting node. During the time gap between channel measurement and data transmission, the channel may change with the location of moving nodes. The unpredictable behavior may cause a mismatch between the weight of beams and the instantaneous channel and the inter‐beam interference in the data transmission phase. In order to obtain the closed form expected outage probability, we categorize the behavior of nodes according to whether the inter‐beam interference exists or not and the number of received interference beams. The probability of each category and the closed form outage probability of an instantaneous MU‐MIMO transmission of each category are derived. Additionally, the expected throughput of an MU‐MIMO transmission which changes with the number of receiving nodes is obtained, and the optimal value of receiving nodes to maximize the expected throughput is discussed. Numeric results show the unpredictable inter‐beam interference degrades the outage probability performance. Reducing the duration of the time gap could improve the expected outage probability and expected throughput.

In this paper, we investigate the per-tier outage probability of multiuser multiple-input multiple-output (MU-MIMO) transmissions in heterogeneous networks (HetNets) with joint interference constraint. In the tier of cellular cell, user equipment (UE) is required to report measured channel information and the base station (BS) adopts ZF-based precoding MU-MIMO transmission to achieve multiuser diversity gain. With the constraint of cross-tier interference and unpredicted inter-beam interference, we derive the closed-form expression of outage probability of downlink MU-MIMO transmissions. Considering the capacity of nodes in the tier of ad hoc networks, a max-SINR scheduler and codebook-based MU-MIMO transmission are employed. The scheduler selects the best receiving nodes for each beam in predefined codebook according to measured signal to interference plus noise ratio (SINR), and the transmitting node performs data transmissions using orthogonal beams. In the presence of inter-node interference, inter-beam interference, and cross-tier interference, we obtain the closed-form expression of outage probability of MU-MIMO transmissions when downlink or uplink transmissions occur in cellular cell. Additionally, in case that the outage probability in ad hoc networks should satisfy quality of service (QoS) requirement, a restricted area in cellular cell in which the outage probability in ad hoc networks is not greater than a required threshold is explored. Numerical results show that the unpredictable inter-beam interference in cellular cell degrades the outage probability slightly. The restricted area increases with the outage probability threshold.

Terahertz (THz) communication is a key enabler for 6G wireless networks but suffers from severe path loss and dynamic blockage, making conventional MAC protocols inefficient. This paper proposes a reconfigurable intelligent surface–based deep reinforcement learning MAC (RIS‐DRL‐MAC) framework that enables cross‐layer optimisation between the physical and MAC layers. By embedding RIS perception features—such as equivalent channel gain and link stability—into the state space and jointly optimising beam direction, channel access and RIS phase configuration through a distributed twin delayed deep deterministic policy gradient (TD3) algorithm, the protocol achieves adaptive environment control. Simulation results show that, under dynamic blockage and high‐load conditions, RIS‐DRL‐MAC improves network throughput by up to 90%, reduces access delay by 50% and maintains over 90% link availability compared with baseline schemes. The proposed method establishes a closed loop of sensing, decision and environment reconfiguration, providing an effective solution for reliable and energy‐efficient THz mesh networking.

Joint hybrid beamforming and underlay spectrum sharing in sixth-generation (6G) massive multiple-input multiple-output (MIMO) Internet-of-Things (IoT) networks yields a non-convex mixed continuous-discrete problem involving constant-modulus analog precoding, subchannel-dependent digital precoding, and binary link activation. This paper develops DEBKA, a training-free optimizer that assigns different search roles to two complementary mechanisms: a BKA-inspired Cauchy-Gaussian attack for local refinement and adaptive DE/current-to-pbest migration for population-difference exploration. These operators are coupled with success-history parameter updates, a rejected-parent archive, constant-modulus-preserving decoding, power normalization, and feasibility-first selection. The methodological contribution therefore lies in the phase-specific BKA-DE architecture and its problem-specific constraint pipeline, rather than in claiming the individual invention of JADE components. Simulations use a simplified geometric mmWave channel model inspired by 3GPP TR 38.901 and compare DEBKA with ten locally implemented baselines over 30 independent runs. Under the default configuration, DEBKA attains 15.87 ± 0.19 bps/Hz, 27.5% above MO-AltMin and 8.1% above BKAPI, and reaches the 1% convergence criterion in 185 ± 12 iterations. Ablation, sensitivity, robustness, and runtime results support the contribution of the coupled search and constraint-handling design within the evaluated scenarios. These results do not establish global optimality or deployment readiness; validation with imperfect channel state information, standardized channel generation, and hardware experiments remains necessary.