Research and Development: Applied Research
Description of company:
Research in the area of wireless communication. Topics in focus are: radio access technologies, advanced receivers, advanced antenna systems and propagation. Active in the specification of 2G, 3G and systems beyond 3G (4G).
Recently, a MIMO transmission scheme was included into the WCDMA specification (Rel-7). This MIMO scheme contain rank adaptation, precoding and is based on the multi codeword principle. This means that for each 2ms TTI, the network decides on the number of transport blocks (rank adaptation) and a beamforming weight for each transport block (precoding). Each transport block is separately turbo encoded to facilitate the use of successive interference cancelling on the receiver side. The MIMO scheme standardized in this release of the specification support up to 2 transmit antennas.
One way to extend the coverage of the MIMO channel would be to increase the number of transmit antennas. This can be done in a number of ways, but one attractive extension would be to apply a space-time code on each of the transmitted data streams. The space-time code in WCDMA is termed space-time transmit diversity (STTD) and is based on the well known Alamouti code. This means that up to 2 separately encoded data streams can be transmitted. But since each stream is STTD encoded, it can be transmitted from 2 antennas. Since the space-time code provides some extra diversity better performance can be expected for lower SINRs.
The aim with this thesis project is to define a MIMO scheme based on applying STTD to the currently defined MIMO scheme. The work would consist of defining the MIMO scheme, deriving suitable receiver algorithms and to evaluate the performance by means of computer simulations.
180 points in Electrical Engineering, Engineering Physics or Computer Engineering or corresponding programs.
Good knowledge in digital communication theory and signal processing.
Good programming skill in C++ and /or MATLAB
Preferred Starting Date: 2007-06-01
Required Scope: 20 points
Sen. Specialist, Multi-Antenna Concepts
+46 8 7570703
Manager, Access Technologies
+46 8 4045140
See job description
Last day to apply: 2007-05-30
Form of employment: Thesis/Final reports