Movable antenna (MA) systems can reshape the wireless channel by repositioning antenna elements in a confined region, but most existing MA optimization methods depend on perfect channel state information (CSI). This paper studies robust joint transmit beamforming and antenna-position optimization for a downlink multiple-input single-output (MISO) MA system with imperfect CSI. Instead of treating CSI errors as unstructured channel perturbations, we introduce bounded uncertainties directly into physical multipath parameters, including path-gain amplitudes and angular parameters. The resulting worst-case signal-to-noise ratio (SNR) design is approximated through discrete sampling and a harmonic-mean surrogate that penalizes weak channel realizations. An alternating optimization algorithm is then developed, where transmit beamforming is updated on the complex sphere manifold, and antenna positions are optimized via a sequential grid search. Simulation results show that the proposed robust design yields higher SNR performance than non-robust designs and the fixed-position antenna (FPA) baseline.

5G mobile networks are envisioned to support both evolved mobile broadband (eMBB) and ultra-reliable and low latency communications (URLLC), which may coexist and interfere with each other in the same service cell in many scenarios. In this paper, we propose a dynamic 2-dimension bitmap resource indication to cancel eMBB services with a finer uplink cancellation granularity and a lower probability of false cancellation. Meanwhile, a resource indication based power control method is introduced to dynamically indicate different power control parameters to the user equipment (UE) based on different time-frequency resource groups and the proportion of overlapping resources, by which the reliability of URLLC transmission is guaranteed while the impact on the performance of the eMBB service is minimized. Furthermore, a dynamic selection mechanism is proposed to accommodate the varying cases in different scenarios. Extensive system level simulations are conducted and the results show that about 10.54% more URLLC UE satisfy the requirements, and the perceived throughput of eMBB UE is increased by 23.26%.

This paper presents a novel de-embedding technique of packaged high-power transistors. With the proposed technique, the packaged model of the power amplifier (PA) tube can be divided into the frequency independent de-embedded intrinsic device (DID) and the frequency dependent internal parasitic network (IPN), which is of great help in reducing the design complexity of a broadband PA. Different from the conventional technique of parasitic extraction, the proposed technique only requires external measurements. The frequency independent characteristic of DID is verified and the IPN is modeled and calibrated for a 50 W gallium-nitride (GaN) transistor. At last, a broadband Doherty PA is fabricated with the de-embedding technique. According to the measured results, the PA exhibits satisfactory power and efficiency performance.