Search results for "Diversity scheme"

showing 3 items of 3 documents

Joint LMMSE equalizer for HSDPA in full-rate space time transmit diversity schemes

2005

This contribution presents a joint linear minimum mean square error (LMMSE) equalizer for full-rate space-time transmit diversity multi-code schemes based on W-CDMA, featuring two and four transmit antennas. Specifically, high-rate, high load systems are targeted, in order to analyze the high speed downlink packet access (HSDPA) of 3GPP Release 6. We derive an equivalent transmission scheme to equalize the received sufficient statistic in a single stage. To reduce the effects of multipath and multiuser interference, and to provide spatial and frequency diversity at the receiver, an LMMSE equalizer is employed. Computer simulations confirm that the proposed schemes achieve robust performance…

Minimum mean square errorComputer scienceSettore ING-INF/03 - Telecomunicazionileast mean squares methodsComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKSEqualizerAdaptive equalizerData_CODINGANDINFORMATIONTHEORYFull RateTransmit diversityTransmission (telecommunications)3G mobile communicationantenna arrayfading channelTelecommunications linkdiversity receptionComputer Science::Networking and Internet ArchitectureElectronic engineeringequaliserFadingMultipath propagationComputer Science::Information TheoryCommunication channelDiversity scheme
researchProduct

An OFDM Receiver Exploiting Multipath Diversity

2008

We propose a novel receiver structure, to be employed with standard Orthogonal Frequency Division Multiplexing transmitters, capable of exploiting the multipath diversity of wireless channels. The proposed technique is based on cancellation of inter-block interference arising in the guard interval and linear detection techniques. It features a low implementation complexity and is easily generalized to MIMO systems and non-linear detection techniques.

Orthogonal frequency-division multiplexingbusiness.industryComputer scienceComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKSDetectorInterference (wave propagation)Antenna diversityGuard intervalElectronic engineeringWirelessRake receiverbusinessComputer Science::Information TheoryDiversity schemeComputer networkCommunication channel
researchProduct

Effects of Temperature and Humidity on Radio Signal Strength in Outdoor Wireless Sensor Networks

2015

Many wireless sensor networks operating outdoors are exposed to changing weather conditions, which may cause severe degradation in system performance. Therefore, it is essential to explore the factors affecting radio link quality in order to mitigate their impact and to adapt to varying conditions. In this paper, we study the effects of temperature and humidity on radio signal strength in outdoor wireless sensor networks. Experimental measurements were performed using Atmel ZigBit 2.4GHz wireless modules, both in summer and wintertime. We employed all the radio channels specified by IEEE 802.15.4 for 2.4GHz ISM frequency band with two transmit power levels. The results show that changes in …

ta113ta213radio signal strengthComputer scienceFrequency bandbusiness.industryRadio Link ProtocolhumiditytemperatureTransmitter power outputTemperature measurementlaw.inventionlawMobile wireless sensor networkElectronic engineeringWirelesslämpötilaTelecommunicationsbusinesswireless sensor networksWireless sensor networkDiversity scheme
researchProduct