Graduate School and Research Center in Digital Sciences

Fundamental limits of cache-aided wireless BC: Interplay of coded-caching and CSIT feedback

Zhang, Jingjing; Elia, Petros

ALLERTON 2016, 54th Annual Allerton Conference on Communication, Control, and Computing, September 27-30, 2016, Monticello, IL, USA / Also on ArXiv

Building on the recent coded-caching breakthrough by Maddah-Ali and Niesen, the work here considers the K-user cache-aided wireless multi-antenna (MISO) symmetric broadcast channel (BC) with random fading and imperfect feedback, and analyzes the throughput performance as a function of feedback statistics and cache size. In this setting, our work identifies the optimal cache-aided degrees-of-freedom (DoF) within a factor of 4, by identifying near-optimal schemes that exploit the new synergy between coded caching and delayed CSIT, as well as by exploiting the unexplored interplay between caching and feedback-quality. The derived limits interestingly reveal that -- the combination of imperfect quality current CSIT, delayed CSIT, and coded caching, guarantees that -- the DoF gains have an initial offset defined by the current CSIT quality, and then that the additional gains attributed to coded caching are exponential, in the sense that any linear decrease in the required DoF performance, allows for an exponential reduction in the required cache size.

Document Doi Arxiv Bibtex

Title:Fundamental limits of cache-aided wireless BC: Interplay of coded-caching and CSIT feedback
Department:Communication systems
Eurecom ref:4744
Copyright: Allerton
Bibtex: @inproceedings{EURECOM+4744, doi = {}, year = {2016}, title = {{F}undamental limits of cache-aided wireless {BC}: {I}nterplay of coded-caching and {CSIT} feedback}, author = {{Z}hang, {J}ingjing and {E}lia, {P}etros}, booktitle = {{ALLERTON} 2016, 54th {A}nnual {A}llerton {C}onference on {C}ommunication, {C}ontrol, and {C}omputing, {S}eptember 27-30, 2016, {M}onticello, {IL}, {USA} / {A}lso on {A}r{X}iv}, address = {{M}onticello, {UNITED} {STATES}}, month = {09}, url = {} }
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