摘要:
An apparatus and method for hierarchical modulation and demodulation in a wireless communication network are provided. A hierarchical modulation apparatus may map information bits to a plurality of levels based on a predetermined level map, may generate an error verification code for each of the levels based on the information bits mapped to the levels, may generate coded information bits for each of the levels, and may map bits in a predetermined position among the coded information bits, to Pulse-Position Modulation (PPM) symbols in a sequence of the levels.
摘要:
An apparatus and method for UpLink (UL) radio resource allocation in a wideband wireless communication system are provided. In a method of operating a Relay Station (RS) for UpLink (UL) radio resource allocation in a wideband wireless communication system, the method includes relaying to a Base Station (BS) a resource request message of at least one or more Mobile Stations (MSs); receiving data from the at least one or more mobile stations; if the received data is non-real time traffic, queuing the data received from the mobile stations according to a traffic type; and requesting the base station to allocate necessary radio resources by checking a queue status. Accordingly, a delay can be reduced when the UL resource is allocated to an relay station for real time traffic.
摘要:
Provided is a multi-hop wireless mobile communication system where a plurality of nodes exist. To select a serving node to be provided with a service, a Mobile Station (MS) receives relay information provided for serving node selection from at least two nodes and selects a first mode of selecting a node that requires the minimum time for unit data transmission/reception as the serving node or a second mode of selecting a node that can transmit and receive the maximum data per unit time as the serving node, based on the received relay information, in order to select the serving node.
摘要:
Provided is a multi-hop wireless mobile communication system where a plurality of nodes exist. To select a serving node to be provided with a service, a Mobile Station (MS) receives relay information provided for serving node selection from at least two nodes and selects a first mode of selecting a node that requires the minimum time for unit data transmission/reception as the serving node or a second mode of selecting a node that can transmit and receive the maximum data per unit time as the serving node, based on the received relay information, in order to select the serving node.
摘要:
A communication method of a coordinator in a bidirectional event transmission sensor network comprising a sensor node and the coordinator is provided. The method includes sensing, in an uplink section, whether a signal having energy greater than or equal to a predetermined magnitude is received, the signal indicating occurrence of an uplink event detected by the sensor node, and transmitting, to the sensor node in a downlink section, a synchronization packet that is used for receiving the uplink event or for transmitting a downlink event in response to the coordinator detecting the downlink event or sensing the signal having energy greater than or equal to the predetermined magnitude in the uplink section. The bidirectional event transmission sensor network has a structure of a super frame that includes at least one standby slot (SS) including the uplink section and the downlink section.
摘要:
A method and apparatus for notifying status of an MN in a WLAN system using VLC are provided, in which an AP allocates a first predetermined number of time slots per frame as unallocated slots, for status notification of an initially accessing MN and allocates a second predetermined number of time slots per frame as reserved slots, for status notification of an initially accessing MN and uplink data transmission of an MN, and the MN transmits a visible light signal carrying status information about the MN in one of an unallocated slot and a reserved slot, if the MN initially accesses the AP.
摘要:
A method for retransmitting data when data transmission/reception has failed in a wireless LAN system using visible light communication. A mobile node searches a received frame for a fast feedback slot allocated for retransmission information when momentary data transmission/reception failure has occurred. One mini-slot from among the plurality of mini-slots is selected from the fast feedback slot. The mobile node transmits a fast feedback message, including information for retransmission, to an access point by using the selected mini-slot.
摘要:
Provided are an ARQ apparatus and method for a multihop system in a broadband wireless access communication system. The ARQ method of a relay includes determining if the relay successfully receives specific data from a source and transmitting the specific data to a destination; receiving feedback data from the destination and determining if the destination successfully receives the specific data; generating feedback data including data indicating if the relay and the destination successfully receive the specific data, and outputting the feedback data to the source; and retransmitting the specific data, when the relay successfully receives the specific data but the destination fails to receive the specific data. Accordingly, when the MH-BTS successfully receives the data from the source but the destination fails to receive the data, the source does not retransmit same data to the MH-BTS.
摘要:
A method is provided for transmitting a packet data unit (PDU) by a transmitter in a wireless mobile communication system. The method includes determining at least one desired transmission PDU, determining a modulation scheme corresponding to the number of PDUs, and transmitting a first indicator value indicating the number of PDUs and the modulation scheme, transmitting the PDUs, receiving a second indicator value indicating a reception state of the PDUs, from a receiver that receives the PDUs, determining a new PDU or a retransmission PDU according to the second indicator value, and determining a modulation scheme corresponding to the number of the determined PDUs, and transmitting a third indicator value indicating the number of PDUs and the modulation scheme, and the corresponding PDUs.
摘要:
A low power radio device and a radio resource sharing method for the low power radio device are provided. In the low power radio device, a channel state (CS) is detected by carrier sensing before transmission of each frame to reduce interference and a need of retransmission of each frame, accordingly, reducing energy consumption.