114 research outputs found
Capacity of Cellular Networks with Femtocache
The capacity of next generation of cellular networks using femtocaches is
studied when multihop communications and decentralized cache placement are
considered. We show that the storage capability of future network User
Terminals (UT) can be effectively used to increase the capacity in random
decentralized uncoded caching. We further propose a random decentralized coded
caching scheme which achieves higher capacity results than the random
decentralized uncoded caching. The result shows that coded caching which is
suitable for systems with limited storage capabilities can improve the capacity
of cellular networks by a factor of log(n) where n is the number of nodes
served by the femtocache.Comment: 6 pages, 2 figures, presented at Infocom Workshops on 5G and beyond,
San Francisco, CA, April 201
An ML-assisted OTFS vs. OFDM adaptable modem
The Orthogonal-Time-Frequency-Space (OTFS) signaling is known to be resilient
to doubly-dispersive channels, which impacts high mobility scenarios. On the
other hand, the Orthogonal-Frequency-Division-Multiplexing (OFDM) waveforms
enjoy the benefits of the reuse of legacy architectures, simplicity of receiver
design, and low-complexity detection. Several studies that compare the
performance of OFDM and OTFS have indicated mixed outcomes due to the plethora
of system parameters at play beyond high-mobility conditions. In this work, we
exemplify this observation using simulations and propose a deep neural network
(DNN)-based adaptation scheme to switch between using either an OTFS or OFDM
signal processing chain at the transmitter and receiver for optimal
mean-squared-error (MSE) performance. The DNN classifier is trained to switch
between the two schemes by observing the channel condition, received SNR, and
modulation format. We compare the performance of the OTFS, OFDM, and the
proposed switched-waveform scheme. The simulations indicate superior
performance with the proposed scheme with a well-trained DNN, thus improving
the MSE performance of the communication significantly
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