The research profile of this division is centered around different types of communication. The division primarily works with wireless communications applications, theoretical studies of communication and the mechanisms used to transmit information over a communication medium. More specifically, the division's research activities can be divided into the following topics:
Channel measurements and modeling
Channel measurements and modeling have a long tradition within the group and currently the activities are focused on multiple-input/multiple-output (MIMO) channels and systems with ultra-wide bandwidths (UWB). The group has a unique set of channel sounding devices, with very high performance. Data from measurement campaigns are used to build and adapt models of previously not studied propagation channels. Research results from these activities are used both for international standardization work and for development of new radio transmission methods.
Algorithm development for digital transmitters and receivers
An integrated part of the design of new wireless communication systems is the study of algorithms with low implementation complexity, performing close to the theoretically optimal methods for transmission and synchronization. The focus of this topic is on such algorithms for time/frequency synchronization and detection/decoding.
Transmission theory/Digital communications
Work in this field centers on methods for wireless communication. Bandwidth-efficient methods -- those that carry many bits per hertz of bandwidth -- are of special interest. The group studies new error-correction coding and speech and image coding methods, all with this aim. There are also projects in powerline communication and spread spectrum transmission.
The research within information theory is focused on understanding the underlying factors that determine the error correcting capabilities of convolutional codes. In addition to structural properties of convolutional encoders, development and analyses of efficient decoding algorithms for (block and) convolutional codes are covered. Presently, efforts are concentrated on construction of and decoding methods for codes on graphs. Using graph-based methods a rate R=5/20 convolutional code with overall constraint length 67 was constructed. Its free distance was determined to be as large as 120.
Antenna system design
The research in this topic started in 2004 as a joint venture with the Electromagnetic Theory Group (now part of the EMN Division). The main interest is in how advanced antenna systems can be optimized for wireless communications, given their interaction with the surroundings (including the channel and nearby objects). In this context, we run projects relating to antenna system design for handset and base station, vehicles, body area networks, ultrahigh field magnetic resonance imaging (UHF-MRI), etc.