Advanced NOMA Assisted Semi-Grant-Free Transmission Schemes for Randomly Distributed Users

Grant-Free Massive NOMA: Outage Probability and Throughput

In this paper, we consider a massive uncoordinated non-orthogonal multiple access (NOMA) scheme where devices have strict latency requirements and no retransmission opportunities are available. Each device chooses a pilot sequence from a predetermined set as its signature and transmits its selected pilot and data simultaneously. A collision occurs when two or more devices choose the same pilot ...

Multi-User Detection Based on Structured Compressive Sensing for Uplink Grant-Free NOMA

Compared to classical orthogonal multiple access (OMA) techniques, non-orthogonal multiple access (NOMA) can support more users using the same wireless resources, which is expected to support massive connectivity for future 5G systems. Furthermore, to reduce the transmission latency and signaling overhead, grant-free transmission is highly expected in the uplink NOMA systems, where user activit...

Optimal Transmission Ranges for Randomly Distributed Packet Radio Terminals

In multihop packet radio networks with randomly distributed terminals, the optimal transmission radii to maximize the expected progress of packets in desired directions are determined with a variety of transmission protocols and network configurations. It is shown that the FM capture phenomenon with slotted ALOHA greatly improves the expected progress over the system without capture due to the ...

ERC Advanced Grant 2016

Free Steering Update Schemes for Distributed Flow Control in Networks

We study two adaptive, distributed optimal flow control algorithms for a virtual circuit flow control in a decentralized network. These algorithms are based on greedy heuristics. Each virtual circuit (or user) attempts to adjusts its message rate to achieve an ideal tradeoff point between high throughput and low delay. The first algorithm is the bottleneck flow control algorithm where each user...