Wireless Local Area Networks with Multiple-Packet Reception Capability

TL;DR

This paper explores how multiuser detection (MUD) techniques can enable multiple packets to be received simultaneously in WLANs, significantly increasing capacity and efficiency beyond traditional single-packet reception systems.

Contribution

It introduces a joint MAC-PHY protocol leveraging MPR capabilities, proves a super-linearity throughput increase with MPR, and optimizes backoff algorithms for enhanced WLAN performance.

Findings

System throughput per unit cost increases with MPR capability.

Optimal backoff factor grows with the number of packets received simultaneously.

Proposed protocol integrates advanced PHY-layer detection with MAC-layer control.

Abstract

Thanks to its simplicity and cost efficiency, wireless local area network (WLAN) enjoys unique advantages in providing high-speed and low-cost wireless services in hot spots and indoor environments. Traditional WLAN medium-access-control (MAC) protocols assume that only one station can transmit at a time: simultaneous transmissions of more than one station causes the destruction of all packets involved. By exploiting recent advances in PHY-layer multiuser detection (MUD) techniques, it is possible for a receiver to receive multiple packets simultaneously. This paper argues that such multipacket reception (MPR) capability can greatly enhance the capacity of future WLANs. In addition, it provides the MAC-layer and PHY-layer designs needed to achieve the improved capacity. First, to demonstrate MUD/MPR as a powerful capacity-enhancement technique, we prove a "super-linearity" result, which states that the system throughput per unit cost increases as the MPR capability increases. Second, we show that the commonly deployed binary exponential backoff (BEB) algorithm in today's WLAN MAC may not be optimal in an MPR system, and that the optimal backoff factor increases with the MPR capability: the number of packets that can be received simultaneously. Third, based on the above insights, we design a joint MAC-PHY layer protocol for an IEEE 802.11-like WLAN that incorporates advanced PHY-layer blind detection and MUD techniques to implement MPR