Abstract:
A method is provided which improves reliability of channel estimation in a digital communication system by reducing the ambiguity in the recognition of received symbols evaluated for the channel estimation. A data word transmitted according to a first mapping of data word values to modulation states is re-transmitted at least once with a second, re-arranged mapping of data word values to modulation states. The second mapping and possible further mappings are generated from the first mapping in a way that the number of different results which can be obtained from combining the transmitted original data symbol and the re-transmitted counterpart data symbol(s) is lower than the number of original modulation states in the first mapping.
Abstract:
A wireless communication apparatus capable of raising the throughput in a multicarrier communication. In the wireless communication apparatus, a subcarrier block deciding part (207) decides the number of subcarriers per subcarrier block in accordance with a fading frequency notified through a notification signal. The greater the fading frequency Δf is, the greater number of subcarriers per subcarrier block is decided by the subcarrier block deciding part (207). That is, the greater the fading frequency Δf is, the smaller number of subcarriers included in each of OFDM symbols is established by the subcarrier block deciding part (207). An MCS deciding part (209) decides, based on CQI notified through a notification signal, an MCS level for each subcarrier block.
Abstract:
A wireless transmission device enabled to improve an error rate performance at a receiver, by acquiring at least one of frequency diversity effect and a time diversity effect while keeping the interference resistance which is acquired by diffusion. In this transmission device, a modulation unit (101) modulates data to create a modulation symbol having in-phase components and quadrature components. An IQ individual spreading unit (102) arranges the diffusion chips, which are obtained by spreading the modulation symbol, of the in-phase components and the quadrature components, in areas extending in diffusion domains set individually for the in-phase components and the quadrature components. An IQ combining unit (103) combines the arranged spreading chips of the in-phase components and the quadrature components.
Abstract:
A radio transmitting apparatus and the like for improving the reception error rate characteristic. In this apparatus, a data modulating part (121) modulates a data signal to provide a modulated symbol. A Q-inverting part (125) generates a symbol that corresponds to the modulated symbol provided by the data modulating part (121) and that, when combined with the modulated symbol, becomes a signal having a particular value. A multiplexing part (110) multiplexes the modulated symbol provided by the data modulating part (121) with the corresponding symbol generated by the Q-inverting part (125) to provide a multiplexed signal.
Abstract:
In order to appropriately control transmit power of a common channel for an MBMS (Multimedia Broadcast/Multicast Service) so as not to become excessive, a mobile station 1 transmits a TPC command for an S-CCPCH to a base station through an uplink DPCH1 and a mobile station 2 transmits a TPC command for an S-CCPCH to the base station through an uplink DPCH2. When either one of the TPC command for the S-CCPCH transmitted from the mobile station 1 and the TPC command for the S-CCPCH transmitted from the mobile station 2 is a TPC command instructing “Up”, the base station increases transmit power of the downlink S-CCPCH and decreases transmit power of the downlink S-CCPCH when both TPC commands instruct “Down”.
Abstract:
A radio communication system and scheduling method where, when data are transmitted from a plurality of transmit antennas to respective different mobile station apparatuses, all the mobile station apparatuses precisely receive data addressed thereto. A scheduler (104) performs scheduling that determines a data transmit order, depending on the numbers of receive antennas of the respective mobile station apparatuses, and notifies a transmit antennas assignment signal generator (124) of which transmit antenna is assigned which mobile station apparatus's sub-stream as the scheduling result. A number of receive antennas notifying signal decoder (122) decodes the number of receive antennas notifying signals and notifies the number of the receive antennas of each mobile station apparatus to the scheduler (104). The transmit antennas assignment signal generator (124) generates the transmit antennas assignment signal indicating which transmit antenna is assigned which mobile station apparatus's sub-stream.
Abstract:
A retransmission request signal creation section (119) outputs an ACK signal or NACK signal to a NACK signal counting section (120) based on the result of error detection by an error detection section (118), the NACK signal counting section (120) counts, for each communication mode, the number of NACK signals output (that is, the number of data retransmissions) before an ACK signal is output from the retransmission request signal creation section (119), and a table rewriting section (121) compares the number of retransmissions counted by the NACK signal counting section (120) with a predetermined threshold value for the number of retransmissions, and rewrites the contents of a communication mode table (102) based on the result of this comparison.
Abstract:
In order to perform appropriate reception quality control on each mobile station in a multimedia broadcast/multicast service, a layered coding section 101 encodes input data by dividing the input data into two layers and obtains a first layer code string and a second layer code string. The first layer code string is input to a CRC code addition section 102 and a CRC code for an error inspection is added thereto at every predetermined block. On the other hand, the second layer code string is input to a CRC code addition section 103 and a CRC code for an error inspection is added thereto at every predetermined block. The first layer code string and the second layer code string with the CRC codes added are input to a layered modulation section 104 and the layered modulation section 104 modulates a plurality of code strings coded by being divided into a plurality of layers in such away that error rates differ hierarchically among the plurality of code strings and a radio section 105 sends the modulated symbol.
Abstract:
A reception power measurement section 107 measures reception power from received data. A transmission power information extracting section 106 extracts information of transmission power of a dedicated channel of mobile equipment included in received data. A condition setting section 108 calculates a transmission parameter of packet data and transmission power in scheduled mobile equipment using information of reception quality, reception power and transmission power of the dedicated channel, and outputs information of the calculated parameter and transmission power command information to channel coding sections 111-1 to 111-n. The channel coding sections 111-1 to 111-n code transmission data including transmission power command information and transmission parameter information to be notified to the scheduled mobile equipment. This makes it possible to perform communications based on suitable resource management in an uplink.
Abstract:
A wireless communication apparatus and a response control method wherein in a case of applying Persistent Allocation (PA) to MU-MIMO, the increase in the resources to be used in the feedback can be precluded. In a terminal, a response control unit causes, based on the type of downstream allocation control information, on an error detection result obtained by an error detecting unit and on a response rule table, a response signal to be transmitted by use of an upstream response resource designated in the downstream allocation control information. In the response rule table used in reception of a notification of MU-MIMO reallocation, respective different types of response signals are associated with a first case where there are no errors in the received downstream data of the designated resource designated in the downstream allocation control information received before that notification, a second case where the notification of MU-MIMO reallocation is successfully received and further there are no errors in the received downstream data of the designated resource, and a third case where the notification of MU-MIMO reallocation is not successfully received and further there are any errors in the received downstream data of the designated resource.