TY - GEN
T1 - Eliminating channel feedback in next-generation cellular networks
AU - Vasisht, Deepak
AU - Kumar, Swarun
AU - Rahul, Hariharan
AU - Katabi, Dina
N1 - Funding Information:
We thank the NETMIT group, Arthur Berger, our reviewers and our shepherd, Deepak Ganesan, for their insightful comments. This work is funded by MIT Lincoln Laboratory. We thank members of the MIT Center for Wireless Networks and Mobile Computing: Amazon, Cisco, Google, Intel, Mediatek, Microsoft, ST Microelectronics and Telefonica for their interest and support.
Publisher Copyright:
© 2016 Copyright held by the owner/author(s).
PY - 2016/8/22
Y1 - 2016/8/22
N2 - 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.
AB - 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.
KW - FDD systems
KW - LTE
UR - http://www.scopus.com/inward/record.url?scp=84986626480&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84986626480&partnerID=8YFLogxK
U2 - 10.1145/2934872.2934895
DO - 10.1145/2934872.2934895
M3 - Conference contribution
AN - SCOPUS:84986626480
T3 - SIGCOMM 2016 - Proceedings of the 2016 ACM Conference on Special Interest Group on Data Communication
SP - 398
EP - 411
BT - SIGCOMM 2016 - Proceedings of the 2016 ACM Conference on Special Interest Group on Data Communication
PB - Association for Computing Machinery
T2 - 2016 ACM Conference on Special Interest Group on Data Communication, SIGCOMM 2016
Y2 - 22 August 2016 through 26 August 2016
ER -