Interference multiple access wireless network demonstration enabled by real-time multiuser detection

Abstract

In recent outdoor, over-the-air tests and simulations, DARPA demonstrated greater than 3X improvement in aggregate wireless network throughput and latency compared to the 802.11b Wireless Local Area Network. This achievement is based on allowing multiple users to simultaneously use the same channel (time, frequency, code, etc.) without requiring a centralized infrastructure for coordination and spectrum preplanning. DARPA has developed new multiuser detection (MUD) algorithms that make it possible to exploit multi-access interference to increase network capacity. A key program goal is to apply these algorithms to next-generation warfighter communications systems for substantial capacity, latency and scalability improvements.Index Terms -multi-access communication, wireless LAN, local area networks, metropolitan area networks.

A MUD/rate selection tool for cognitive radios in packet based asynchronous Gaussian multiple access channels

“…to the whitened matched filter outputs Y w , where H = Q H A from (6). Since the filter is linear, normality is preserved and we can express the capacity of the channel -MMSE filter cascade as:…”

“…For both types of coexistence, then, a critical enabler is, indeed, the MUD receiver, but having a MUD doesn't guarantee a successful IMA link. Currently, prototype MUD-based IMA systems such as the DIMA system described in [6] must rely upon coordination of all interfering users via an IMA medium access controller (MAC) to ensure the specific details governing the scenario like powers and rates, do not "break the MUD" receivers that have been implemented within the IMA radios.…”

Cognitive coexistence: A throughput study of MUD-enhanced opportunistic spectrum access

“…Such a system of CCI-tolerant nodes would rely upon the IMA-MAC to assign a subset of requesting transmitter nodes to the same channel [11], [12], [13] and/or control powers and rates among the participating interfering nodes.…”