Cooperative Slotted Aloha for Multi-Base Station Systems

Covert Communication over Slotted ALOHA Systems

This paper uses jamming legitimate transmissions over a slotted ALOHA system as a means of covert communication. The resulting covert channel is found to be source dependent, and to have infinite memory. Hence, a characterization of the capacity of covert communication over such a medium is an inherently complex problem. Employing i.i.d. jamming strategies, this paper derives achievable rates f...

Capacity of time-slotted ALOHA systems

t,r;insrnit.. Depending on the presence or absence of ot.lier users, each user will be able to achieve different rates. In particular. certain bit,s n-ill be .received in the absence of other users but not in t,he presence of other users. Since some transniitted bits mill be lost owing to collisions. the capacit.y lve consider is maxiinurn rel iablyreceived rate rather than niasiiiium rel iably...

Performance analysis for a stabilized multi-channel slotted ALOHA algorithm

Asynchronous Interference Mitigation in Cooperative Base Station Systems

Cooperative transmission by base stations (BSs) can significantly improve the spectral efficiency of multiuser, multicell, multiple input multiple output (MIMO) systems. We show that contrary to what is often assumed in the literature, the multiuser interference in such systems is fundamentally asynchronous. Intuitively, perfect timing-advance mechanisms can be best only ensure that the desired...

Slotted Aloha with multi-AP diversity and APS transmit beamforming

Slotted Aloha is an effective random access protocol and can also be an important element of more advanced media access protocols. This paper investigates slotted Aloha in a radio environment with multiple access points. Specifically, we examine the impact of multi-access-point (multi-AP) diversity on the performance of slotted Aloha. The paper considers both omni-directional (OM) and beamformi...