Autori: Ligia Chira Cremene, Tudor Palade

Editorial: SoftMotor Ltd., The Mediterranean Journal of Electronics and Communications, Vol. 3, No. 3, p.pp.100-109, 2007.

Rezumat:

Our analysis is performed in the context of a study of adaptive
radio techniques, in the attempt to improve link availability and
transmission quality of broadband wireless systems, and especially
to achieve an efficient use of radio resources. We have established
our focus on spatial diversity techniques, and this paper presents a
performance analysis of transmitter and receiver combining techniques for indoor multipath scenarios, in the particular case of an 802.11a PHY. Transmitter diversity based on Alamouti space-time coding schemes have been tested in the following
configurations: 2Tx-1Rx, 2Tx-2Rx, 4Tx-1Rx, 4Tx-2Rx. Considerable improvements of packet error rates (PER), signal-tonoise ratio (SNR) and bit rate have been noticed, compared to
those obtained with no diversity or receiver diversity techniques.
Spatial diversity schemes in the transmitter proved to be especially
efficient in keeping the PER values down, thus distinguishing
themselves as a solution for multipath scenarios. Regarding receiver combing, even if a performance hierarchy of these techniques is already established – based on diversity gain
improvement – we wanted to see which combining technique is better for a particular scenario. The detailed observations will enable us to set the premises for new adaptive techniques or
adaptive combinations.

Cuvinte cheie: Adaptive Techniques, Transmitter and Receiver Diversity, 802.11a PHY