Multi-hop wireless networks remain an important research frontier of
wireless communications. Multi-hop wireless networks are rapidly
deployable to extend the coverage of the Internet, which can be an
economical alternative to building new base stations. Multi-hop
wireless networks are particularly useful for first responders for
disaster relief, and military operations in battlefields. In this
thesis, we study power scheduling issues for multi-hop wireless
networks. Power scheduling, also known as medium access control
consisting of link scheduling, power control and source beamforming,
fundamentally governs the capacity of multi-hop wireless networks.
In the first part of this thesis, the achievable network throughput
of large-scale multi-hop wireless networks is evaluated under a
power scheduling scheme called opportunistic synchronous array
method (O-SAM). Under O-SAM, a large network is partitioned into
many small subnets, and within each subnet, the link with best
channel gain is scheduled for transmission. We examine the impact of
traffic load, network topology and multiple antennas on the
achievable network throughput. Compared with slotted ALOHA, the
throughput of O-SAM is significantly higher. In addition to O-SAM, a
distributed synchronous array method (D-SAM) is proposed, and its
performance is also evaluated.
In the second part of this thesis, we focus on the power scheduling
problem for multi-input multi-output (MIMO) relay networks. A
generalized water filling (GWF) theorem is established for link rate
maximization with multiple power constraints. The corresponding GWF
algorithm is a fast solution to an important class of convex
optimization problems. The GWF algorithm is a useful building block
for joint source and relay optimization for a multiuser MIMO relay
network. We study the power scheduling problems for both uplink and
down- link cases of the multiuser MIMO relay network. A number of
computational strategies are proposed to maximize the sum rate
subject to power constraints or to minimize the sum power subject to
rate constraints.
