摘要:
An apparatus and method for receiving a ranging signal in an OFDMA mobile communication system are provided. The ranging signal receiving apparatus including, a ranging subchannel extractor for extracting subcarrier values with a ranging signal from a (FFT) signal; a plurality of multipliers for code-demodulating the sub-carrier values by multiplying them by a plurality of ranging codes; each of a plurality of correlators for calculating a plurality of differential correlations in a code-demodulated signal received from a corresponding multiplier; each of a plurality of inverse fast Fourier transform (IFFT) processors for IFFT-processing differential correlations received from a corresponding correlator by mapping the differential correlations to predetermined subcarriers and each of a plurality of maximum value detectors for detecting a maximum value in an IFFT signal received from a corresponding IFFT processor and calculating a timing offset using an IFFT output index having the maximum value.
摘要:
An apparatus and a method for controlling uplink power utilizing an open-loop scheme in a mobile communication system using a TDD scheme. According to the apparatus and the method, an AT determines initial uplink transmit power and transmits uplink signals to an AP using the determined initial uplink transmit power, receives downlink signals from the AP, detects a power compensation value compensating for the uplink transmit power, which are determined according to whether an error has occurred in the uplink signals, measures receive power of the downlink signals, and adjusts the uplink transmit power according to the receive power and the power compensation value.
摘要:
The present invention relates to a mobile communication system utilizing an OFDM scheme. In a broadband wireless access communication system utilizing an OFDM/OFDMA scheme, in which uplink time sync between a BS and a SS and the intensity of a BS reception signal are set, and a ranging signal is transmitted from the SS to the BS in order that the SS gives a bandwidth request to the BS. Described herein are a method for constructing a ranging channel, a method for a BS's operating a ranging channel to be used by a SS, a method for receiving ranging codes transmitted SS by SS from the BS to the SS through the ranging channel.
摘要:
An apparatus and method for changing an uplink power control scheme according to mobile status in a TDD mobile communication system are provided. A subscriber station transmits to a base station a power control change request message including information about a requested power control scheme. Upon receipt of the power control change request message, the base station selects a power control scheme for the uplink of the subscriber station and transmits to the subscriber station a power control change command message including information about the selected power control scheme. The subscriber station extracts, upon receipt of the power control change command message from the base station, the power control scheme information from the power control change command message and selects a power control scheme according to the extracted information.
摘要:
An apparatus and method for assigning subchannels of a transmitter in a communication system. The method includes dividing an entire frequency band into m subcarrier groups; mapping each of the m subcarrier groups to a subcarrier group index, wherein a subchannel includes n subcarriers selected from each of the m subcarrier groups corresponding to a subcarrier group index sequence; determining that a first data is needed to transmit in a first timing point; and assigning a first subchannel in the first timing point using a first subcarrier group index sequence. The first subcarrier group index sequence is different from a second subcarrier group index sequence used for assigning a second subchannel in a second timing point.
摘要:
An apparatus and method for changing an uplink power control scheme according to mobile status in a TDD mobile communication system are provided. A subscriber station transmits to a base station a power control change request message including information about a requested power control scheme. Upon receipt of the power control change request message, the base station selects a power control scheme for the uplink of the subscriber station and transmits to the subscriber station a power control change command message including information about the selected power control scheme. The subscriber station extracts, upon receipt of the power control change command message from the base station, the power control scheme information from the power control change command message and selects a power control scheme according to the extracted information.
摘要:
A method of allocating sub-channel signal interleaving patterns to BSs forming a wireless communication system that divides a frequency band into a plurality of sub-carriers and including a plurality of sub-channels, which are a set of predetermined adjacent sub-carriers. The method includes: creating a basic orthogonal sequence having a length identical to a number of the sub-carriers forming the sub-channel; creating a plurality of sequences having a same length as the basic orthogonal sequence by cyclic-shifting the basic orthogonal sequence a predetermined number of times or performing a modulo operation based on a number of the sub-carriers forming the sub-channel, after adding a predetermined offset to the cyclic-shifted basic orthogonal sequence; selecting a predetermined number of sequences corresponding to a number of the BSs from among the plurality of sequences; and allocating the selected sequences as the sub-channel signal interleaving patterns for the BSs.
摘要:
An apparatus and method for changing an uplink power control scheme according to mobile status in a TDD mobile communication system are provided. The communication system comprises a Subscriber Station (SS) for transmitting a power control change request message to a Base Station (BS) to change the power control scheme, and the BS for deciding to change the power control scheme between the open loop power control and closed loop power control, and transmitting a power control change response message the SS including the decided power control scheme.
摘要:
A method of allocating sub-channel signal interleaving patterns to BSs forming a wireless communication system that divides a frequency band into a plurality of sub-carriers and including a plurality of sub-channels, which are a set of predetermined adjacent sub-carriers. The method includes: creating a basic orthogonal sequence having a length identical to a number of the sub-carriers forming the sub-channel; creating a plurality of sequences having a same length as the basic orthogonal sequence by cyclic-shifting the basic orthogonal sequence a predetermined number of times or performing a modulo operation based on a number of the sub-carriers forming the sub-channel, after adding a predetermined offset to the cyclic-shifted basic orthogonal sequence; selecting a predetermined number of sequences corresponding to a number of the BSs from among the plurality of sequences; and allocating the selected sequences as the sub-channel signal interleaving patterns for the BSs.
摘要:
A wireless communication system that divides an entire frequency band into a plurality of subcarrier bands and includes a plurality of subchannels, each of which includes a number of subcarrier bands. The number of subcarrier groups is equal to the number of the base stations included in the system and are generated by classifying the subcarrier bands in a period. For a particular base station, corresponding subcarrier bands are detected from each of the groups according to a sequence. The subcarrier bands detected from each of the groups are assigned as a subchannel for the particular base station. Further, the indexes of the subcarrier groups to which each of subcarriers constituting a subchannel belongs are changed whenever the subchannel is assigned, so as to acquire the desired diversity gain.