Deepak Vasisht,
Swarun Kumar,
Hariharan Rahul,
Dina Katabi
ACM SIGCOMM
2016, Florianópolis, Brazil, August 2016
This paper focuses on a simple, yet fundamental question: Can a node
infer the wireless channels on one frequency band by observing the
channels on a different frequency band? This question arises in
cellular networks, where the uplink and the downlink operate on
different frequencies. Addressing this question is critical for the
deployment of key 5G solutions such as massive MIMO, multi-user MIMO,
and distributed MIMO, which require channel state information.
We introduce R2-F2, a system that enables LTE base stations to infer
the downlink channels to a client by observing the uplink channels
from that client. By doing so, R2-F2 extends the concept of
reciprocity to LTE cellular networks, where downlink and uplink
transmissions occur on different frequency bands. It also removes a
major hurdle for the deployment of 5G MIMO solutions. We have
implemented R2-F2 in software radios and integrated it within the LTE
OFDM physical layer. Our results show that the channels computed by
R2-F2 deliver accurate MIMO beamforming (to within 0.7 dB of
beamforming gains with ground truth channels) while eliminating
channel feedback overhead.
[PDF (5.2MB)]
Bibtex Entry:
@inproceedings{vasisht2016r2f2,
author = "Deepak Vasisht and Swarun Kumar and Hariharan Rahul and Dina Katabi",
title = "{Eliminating Channel Feedback in Next-Generation Cellular Networks}",
booktitle = {ACM SIGCOMM 2016},
year = {2016},
month = {August},
address = {Florianópolis, Brazil}
}