RECENT ADVANCES IN COOPERATIVE TRANSMISSION FOR MIMO NETWORKS

PhD Qualifying Examination


Title: "RECENT ADVANCES IN COOPERATIVE TRANSMISSION FOR MIMO NETWORKS"

by

Mr. Wang Kit WONG


Abstract:

The ever-growing wireless bandwidth requirement is pushing network operators to 
densify base stations (BSs) deployment, which results in multi-tier networks 
consisting of macrocells, femtocells and smallcells. The well-known 
interference issue becomes a significant factor limiting user throughput in 
such dense heterogeneous networks. To avoid interference, previous methods 
orthogonalize channel access in both frequency and time domain. However, these 
approaches often lead to low spectral efficiency. To improve spectral 
efficiency, recent cooperative transmission schemes exploiting cooperation 
between MIMO (Multiple Input Multiple Output) nodes are proposed and shown to 
be more effective.

To realize cooperative transmission, multiple interfering BSs are connected 
with a backhaul link forming a virtual BS, which is often referred to as a 
cooperation cluster. Depending on the cooperation methods, different 
information such as Channel State Information (CSI), user data and user 
scheduling information may be shared among BSs from the same cooperation 
cluster. Based on whether user data are shared among cooperating BSs, the 
cooperative transmission methods can be broadly classified as either Joint 
Transmission (JT) and Interference Alignment (IA). In JT, uses’ data and the 
channel state information (CSI) are shared among BSs within the same 
cooperation cluster. A user receives the same data packet from multiple BSs. To 
reduce control overhead, IA approaches only require sharing of CSI and 
scheduling information among cooperating BSs. In this survey, the 
state-of-the-art cooperative transmission methods of each category are present 
and analyzed in detail. Their strengths and weaknesses in term of achievable 
performance, incurred overhead, robustness, and scalability are discussed. 
Moreover, the open research challenges related to each issue in cooperative 
transmission are also discussed.


Date:			Friday, 23 March 2018

Time:                  	4:00pm - 6:00pm

Venue:                  Room 2611
                         Lifts 31/32

Committee Members:	Prof. Gary Chan (Supervisor)
 			Prof. Cunsheng Ding (Chairperson)
 			Dr. Xiaojuan Ma
 			Dr. Wei Wang


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