面向突发主用户业务的可靠动态频谱接入的信道-令牌注意力机制
Channel-Token Attention for Reliable Dynamic Spectrum Access under Bursty Primary-User Traffic
- Institute of Engineering, Tribhuvan University（特里布万大学工程学院）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
针对突发主用户业务，提出TACAN策略，结合信道-令牌注意力与Transformer优化，在20信道网络中提升存在分组接入成功率、降低时延与可靠性差距，未获得分组吞吐量增益。
AI中文摘要：
动态频谱接入必须在突发主用户活动下协调次用户，同时保持分组可靠性和时延。我们提出TACAN，一种集中式策略，将每个信道表示为包含占用历史和自动调制分类熵的令牌；上下文令牌提供队列类别、时延和用户身份。Transformer编码器从占用贪婪策略进行热启动，并通过近端策略优化进行优化。冻结的策略被训练为在每个时隙中维持信道分配，包括队列为空时。因此，我们在保留的轨迹上重放这些策略，区分待机分配成功、存在分组时的接入以及分组交付。在具有60个主设备和4个次用户的20信道网络中，TACAN实现了92.53%±0.47的存在分组接入成功率，相比之下，Greedy为89.94%，PPO+MLP为83.53%。其相对于Greedy的配对增益为2.59个百分点（参数化95%置信区间1.89-3.29），在所有5个随机种子中均获胜；精确双侧符号检验值为0.0625。该增益从正常主用户负载下的0.57个百分点上升到极端负载下的7.67个百分点。TACAN还将平均交付时延从1.208时隙减少到1.123时隙，将条件用户可靠性差距从9.69个百分点减少到3.15个百分点。每个次用户时隙交付的分组数仍受到达限制（30.12%对比30.11%），因此未声称获得分组吞吐量增益。
英文摘要：
Dynamic spectrum access must coordinate secondary users under bursty primary-user activity while preserving packet reliability and delay. We present TACAN, a centralized policy that represents each channel as a token containing occupancy history and automatic-modulation-classification entropy; a context token supplies queue class, delay and user identity. A Transformer encoder is warm-started from an occupancy-greedy policy and refined with proximal policy optimization. The frozen policies were trained to maintain a channel assignment in every slot, including when queues were empty. We therefore replay them on held-out trajectories and distinguish standby assignment success from packet-present access and packet delivery. In a 20-channel network with 60 primary devices and 4 secondary users, TACAN achieves 92.53% +/- 0.47 packet-present access success, compared with 89.94% for Greedy and 83.53% for PPO+MLP. Its paired gain over Greedy is 2.59 points (parametric 95% CI 1.89-3.29), with wins in all five seeds; the exact two-sided sign-test value is 0.0625. The gain rises from 0.57 points at normal primary-user load to 7.67 points at extreme load. TACAN also reduces mean delivery delay from 1.208 to 1.123 slots and the conditional user-reliability gap from 9.69 to 3.15 points. Delivered packets per SU-slot remain arrival-limited (30.12% versus 30.11%), so no packet-throughput gain is claimed.
