We consider a generalized collision channel model for general multi-user communication systems, an extension of Massey and Mathys' collision channel without feedback for multiple access communications. In our model, there are multiple transmitters and receivers sharing the same communication channel. The transmitters are not synchronized and arbitrary time offsets between transmitters and receivers are assumed. A ``collision" occurs if two or more packets from different transmitters partially or completely overlap at a receiver. Our model includes the original collision channel as a special case. This paper focuses on reliable throughputs that are approachable for arbitrary time offsets. We consider both slot-synchronized and non-synchronized cases and characterize their reliable throughput regions for the generalized collision channel model. These two regions are proven to coincide. Moreover, it is shown that the protocol sequences constructed for multiple access communication remain ``throughput optimal" in the generalized collision channel model. We also identify the protocol sequences that can approach the outer boundary of the reliable throughput region.

翻译：我们考虑一个适用于通用多用户通信系统的广义碰撞信道模型，该模型是Massey和Mathys提出的无反馈多址接入碰撞信道的扩展。在此模型中，多个发射机和接收机共享同一通信信道。发射机之间非同步，且假定发射机与接收机之间存在任意时间偏移。若来自不同发射机的两个或多个数据包在接收机处发生部分或完全重叠，则定义为“碰撞”。原始碰撞信道是本文模型的一种特例。本文聚焦于在任意时间偏移条件下可逼近的可靠吞吐量。我们同时研究时隙同步与非同步情况，并刻画广义碰撞信道模型下这两种情况的可靠吞吐量区域，证明两者一致。此外，研究表明，为多址接入通信设计的协议序列在广义碰撞信道模型中仍保持“吞吐量最优”特性。我们还确定了能够逼近可靠吞吐量区域外边界的协议序列。