Coalitional Games for Transmitter Cooperation in MIMO Multiple Access Channels

Cooperation between nodes sharing a wireless channel is becoming increasingly necessary to achieve performance goals in a wireless network. The problem of determining the feasibility and stability of cooperation between rational nodes in a wireless network is of great importance in understanding cooperative behavior. This paper addresses the stability of the grand coalition of transmitters signaling over a multiple access channel using the framework of cooperative game theory. The external interference experienced by each TX is represented accurately by modeling the cooperation game between the TXs in \emph{partition form}. Single user decoding and successive interference cancelling strategies are examined at the receiver. In the absence of coordination costs, the grand coalition is shown to be \emph{sum-rate optimal} for both strategies. Transmitter cooperation is \emph{stable}, if and only if the core of the game (the set of all divisions of grand coalition utility such that no coalition deviates) is nonempty. Determining the stability of cooperation is a co-NP-complete problem in general. For a single user decoding receiver, transmitter cooperation is shown to be \emph{stable} at both high and low SNRs, while for an interference cancelling receiver with a fixed decoding order, cooperation is stable only at low SNRs and unstable at high SNR. When time sharing is allowed between decoding orders, it is shown using an approximate lower bound to the utility function that TX cooperation is also stable at high SNRs. Thus, this paper demonstrates that ideal zero cost TX cooperation over a MAC is stable and improves achievable rates for each individual user.Comment: in review for publication in IEEE Transactions on Signal Processin

Doing Ethnography, Being an Ethnographer: The Autoethnographic Research Process and I

I examine here Theory and Scholarship (taken to be formalized social scientific frameworks that seek to map out the real world and social actions in an objective fashion) via an autoethnographic lens. Chiefly, I ask how autoethnography as a research method reconfigures them: how may we extend knowledge using autoethnography? While much critique has centered on the "doing" (dispassionately?) versus "being" (going native?) of autoethnography, I argue that such a dichotomy is inherently false. Instead, doing is located within the ethnographer's very being, so that a closer look at the autoethnographic research process is required, from conception to implementation to introspection. I attempt such a processual analysis here: drawing on an earlier social scientific project, I relate the intellectual and social process whereby it was translated into an autoethnography. Using a performative lens to illustrate the dialectical mode of doing and being in the research process, I intersperse portions of personal narrative with academic writing, to enable a disjunctural appreciation of the various layers of interpretation. While the epistemic framework I hold to here is indeed a poststructural one, privileging fragmentation and social situatedness, it also emphasizes continuity and interconnections in the research process

#PandemicFoodPorn: Resilience and Precarity During COVID-19

Journal #65 from Media Rise's Quarantined Across Borders Collection by Rahul Mitra. From India. Quarantined in Michigan, USA. Story about food and culture.I negotiate the complex intersections between making (eating) food while quarantined at home and sharing those pictures on social media, especially as they help us be more resilient in a world that has all-too-suddenly changed forever.Media Rise Publications. Quarantined Across Borders Collection. Edited by Dr Srividya "Srivi" Ramasubramanian

#PandemicFoodPorn: Resilience and Precarity During COVID-19

Journal #65 from Media Rise's Quarantined Across Borders Collection by Rahul Mitra. From India. Quarantined in Michigan, USA. Story about food and culture.I negotiate the complex intersections between making (eating) food while quarantined at home and sharing those pictures on social media, especially as they help us be more resilient in a world that has all-too-suddenly changed forever.Media Rise Publications. Quarantined Across Borders Collection. Edited by Dr Srividya "Srivi" Ramasubramanian