The proposed scheme has the some advantage of dispensing with designing OSS and can be applied to downlink transmission at the cost of loss in the spreading spectrum.
This technique is mainly designed to combat channel fading in downlink transmission by combining the technique of channel coding and that of array diversity, hence increasing the capacity of wireless communications systems and giving diversity gain and coding gain to them.
Andthen study the modulation and demodulation technology in accord with DVB-C hasbeen completed, which are QAM applied in transmission of digital video signal(downstream) and QPSK (upstream) used for interactive communication.
High Speed Down-link Packet Access(HSDPA), which can highly increase the downlink data rate is presented for the unsymmetrical service of uplink and downlink in the 3rd generation mobile communication system.
A scheduling and power allocation algorithm was developed in a combined orthogonal frequency division multiplexing(OFDM) access and spatial multiplexing multiuser multiple input multiple output(MIMO) access environment to introduce diversity gains to fully utilize radio resources.
The comparison results show that the TPDB would be a promising candidate for the downlink transmission if both performance and implementation complexity are considered.
To this effect, this paper addresses a location- and service-aware downlink transmission power allocation problem (DTPA), the solution of which is suitable for the management or control domain of multi-service, WCDMA-based cellular networks.
One side effect of the TP-MAC protocol is that downlink propagation of wake up tones may result in waking up all nodes of the network.
例句来源
From the basic differential euation of spontaneous and stimulatal Raman scattering, we have de-rived the integral solution of high power laser propagation through the atmosphere, and calculated anddiscussed the down-link propagation threshold of various conditions under the standerd atmosphericmodel.
The telecontrol and telemetry system of UAV is an integration radio system which implements telecontrol , telemetry , tracking , positioning and reconnaissance image transmission. This paper introduces an integrated telecontrol and telemetry system, with emphasis on downward datalink design with digitized reconnaissance image. The design is important to telecontrol and telemetry system of UAV.
In this paper, we describe the architecture of passive optical access network incorporating WDM(WDMPON), discuss its key techniques of downstream transmission and upstream transmission. The general features are analyzed, the advantages and shortages of PSPON and WDMPON are also compared.