Digital Beamforming as a Means for Interference Cancellation
Blekinge Institute of Technology, Department of Signal Processing1997 (English)Conference paper (Refereed) Published
The increasing demand for user capacity is one of the major challenges to network operators today. In order to increase the capacity in a mobile radio network, it is desirable to exploit the spatial domain in an efficient way. An array adds spatial domain selectivity in order to improve the Carrier-to-Interference ration (C/I). An adaptive antenna ray can further improve the Carrier-to-Interference ratio (C/I) by suppressing interfering signals. The proposed circular array consists of M elements and combines fixed beamformers with interference cancellors. The fixed beamformers use a weight matrix to form multiple beams. The radius of the circular array is assumed to be half the wavelenght of the signal. The interference cancellor suppresses undesired signals, so called jammers, leaking into the desired beam. The desired signal is filtered out by the fixed beamforming structure. Due to the sidelobes, interfering signals will also, however, be present in this beam. Two alternative strategies may be chosen to cancel these interferers; use the other fixed beam outputs as inputs to an adaptive interference canceller, or demodulate the outputs from the other fixed beams and regenerate clean signals which are used as inputs to adaptive interference cancellers. Results are presented using beamformer weights obtained from an LS minimization as well as minimax.
Place, publisher, year, edition, pages
IdentifiersURN: urn:nbn:se:bth-10085Local ID: oai:bth.se:forskinfo448C17A58A2AEBCCC12568A3002CAA26OAI: oai:DiVA.org:bth-10085DiVA: diva2:838114
International Conference on Optimization Techniques and Applications (ICOTA 98)