摘要:
A cooperative communication method for vehicular communication is provided. The method in which when one vehicle transmits a signal to another vehicle, a signal of a transmission vehicle passes through a roadside device or a plurality of vehicles and thereafter signals having a plurality of paths are transmitted to a reception vehicle, and the reception vehicle combines and demodulates the signals received through the plurality of paths.
摘要:
An apparatus for time synchronization of an orthogonal frequency division multiplexing (OFDM) system oversamples a received signal using a master clock having a frequency at least four times higher than a minimum sampling frequency in a transmission apparatus, sets one of a plurality of oversampled signals to an on-time signal, and shifts each of the remaining oversampled signals by a predetermined time on the basis of the on-time signal. The apparatus for time synchronization calculates a correlation value by correlating each of the shifted signals and the on-time signal with a previously known signal, detects a maximum energy value among the calculated correlation values, and detects a start point of a frame by comparing the maximum energy value with a predetermined threshold value.
摘要:
A method for hybrid media access control for vehicle communication is provided. The method divides a radio channel into time slots, which are predetermined time units, and sets terminals as owners or non-owners for the divided time slots to be able to access the channel. Accordingly, it is possible to reduce the probability of contention by distributed access to the slots and provide a MAC protocol having excellent performance.
摘要:
Provided are a method and a system for transmitting and receiving a warning message that rapidly inform an adjacent hop of a dangerous situation that occurs on a road. The method for transmitting the warning message includes selecting one or more relay vehicles by using distances between vehicles and state information of the vehicles when the dangerous situation occurs on a road or outside, and increasing a warning message sequence number and generating and transmitting a warning message containing an identifier of the relay vehicle and a retransmission time.
摘要:
An apparatus for time synchronization of an orthogonal frequency division multiplexing (OFDM) system oversamples a received signal using a master clock having a frequency at least four times higher than a minimum sampling frequency in a transmission apparatus, sets one of a plurality of oversampled signals to an on-time signal, and shifts each of the remaining oversampled signals by a predetermined time on the basis of the on-time signal. The apparatus for time synchronization calculates a correlation value by correlating each of the shifted signals and the on-time signal with a previously known signal, detects a maximum energy value among the calculated correlation values, and detects a start point of a frame by comparing the maximum energy value with a predetermined threshold value.
摘要:
An automatic gain control method of a receiving apparatus is provided. The automatic gain control method includes low-noise amplifying a signal using a first gain value, amplifying the low-noise amplified signal to a second gain value, determining the first gain value using a strength of the low-noise amplified signal, and determining the second gain value using the signal amplified to the second gain value. Accordingly, the reliability of the automatic gain control may be guaranteed.
摘要:
A safe driving providing system for supporting a safe driving of a vehicle includes: a radar for transmitting a signal of a predetermined frequency bandwidth to a plurality of vehicles, analyzing signals provided by the vehicles, calculating location information and distance information of the vehicles, and finding inter-vehicle distance information of the vehicles based on the location information and the distance information; and a controller for receiving operation speed information from a vehicle information terminal device installed in each vehicle, determining driving safety of the plurality of vehicles based on the received operation speed information and inter-vehicle distance information provided by the radar, and transmitting a warning message for safe driving to the vehicle information terminal device.
摘要:
A safe driving providing system for supporting a safe driving of a vehicle includes: a radar for transmitting a signal of a predetermined frequency bandwidth to a plurality of vehicles, analyzing signals provided by the vehicles, calculating location information and distance information of the vehicles, and finding inter-vehicle distance information of the vehicles based on the location information and the distance information; and a controller for receiving operation speed information from a vehicle information terminal device installed in each vehicle, determining driving safety of the plurality of vehicles based on the received operation speed information and inter-vehicle distance information provided by the radar, and transmitting a warning message for safe driving to the vehicle information terminal device.
摘要:
When supporting the handover from first road side equipment of a plurality of sets of road side equipment and second road side equipment that is adjacent to the first road side equipment to a vehicle, the first road side equipment generates a first channel seizing signal that is longer than that of the second road side equipment in a control channel of an N-th sync interval. The second road side equipment generates a second channel seizing signal that is longer than that of the first road side equipment in a control channel of an (N+1)-th sync interval.
摘要:
When supporting the handover from first road side equipment of a plurality of sets of road side equipment and second road side equipment that is adjacent to the first road side equipment to a vehicle, the first road side equipment generates a first channel seizing signal that is longer than that of the second road side equipment in a control channel of an N-th sync interval. The second road side equipment generates a second channel seizing signal that is longer than that of the first road side equipment in a control channel of an (N+1)-th sync interval.