Abstract:
Provided are a base station apparatus, a terminal device, and a communication method that can realize a small cell network while reducing load on the terminal device, the small cell network including a small cell performing massive MIMO transfer. The base station apparatus of the present invention is a second base station apparatus included in a communication system in which a plurality of the second base station apparatuses capable of acquiring assistance information from a first base station apparatus communicates with a terminal device, the base station apparatus including a codebook that describes a plurality of linear filters, in which the same cell identification number as at least one of the other second base station apparatuses is configured, and a synchronization signal correlated with the cell identification number is transmitted on the basis of the plurality of linear filters after first precoding of the synchronization signal.
Abstract:
Optimal transmit power control is performed in a band other than licensed bands. When the way of specifying transmit power differs between the licensed band and a frequency band other than the licensed band, the expression of the transmit power control is changed to perform transmit power control. A terminal apparatus includes a carrier aggregation radio transmission unit configured to simultaneously transmit a plurality of component carriers, and a transmit power control unit configured to control transmit power of each of the plurality of component carriers, wherein the transmit power control unit calculates a transmit power of a dedicatedly usable first component carrier among the plurality of component carriers in consideration of the transmit power of the first component carrier, and calculates a transmit power of a second component carrier other than the dedicatedly usable first component carrier in consideration of the transmit power of the first component carrier.
Abstract:
More efficient control and stably establishing, securing, and continuing communication using unlicensed bands, in use of the unlicensed bands. A base station apparatus of the present invention is a base station apparatus capable of performing communication with a terminal device, by using a frequency band that can be exclusively used and a frequency band that cannot be exclusively used, by applying a communication scheme, which is applied to the frequency band that can be exclusively used, to the frequency band that cannot be exclusively used, and the base station apparatus instructs the terminal device to perform the communication with the base station apparatus by applying the communication scheme to the frequency band that cannot be exclusively used, by notifying the terminal device of control information necessary for control so as to use the frequency band that cannot be exclusively used in the communication with the terminal device to which the communication scheme is applied, in a state where the frequency band that cannot be exclusively used is not used in the communication with the terminal device to which the communication scheme is applied.
Abstract:
When an unlicensed band is used, a more efficient control is provided, and a communication is established, or ensured and continues by stably using the unlicensed band. According to the present invention, there is provided a base station apparatus which applies a communication scheme applied to a frequency band allowed to be dedicatedly used, to a frequency band of which dedicated use is not allowed, and enables a communicate with a terminal device by using the frequency band of which dedicated use is not allowed, along with the frequency band allowed to be dedicatedly used. In a state where the frequency band of which dedicated use is not allowed is not used for a communication with the terminal device, to which the communication scheme is applied, the terminal device is notified of control information, and thus the communication scheme is applied to the frequency band of which dedicated use is not allowed, and the terminal device is instructed to communicate with the base station apparatus. The control information is required for a control when the frequency band of which dedicated use is not allowed is used in a communication with the terminal device, to which the communication scheme is applied.
Abstract:
Selection of a suitable MCS improves throughput without increasing the number of pieces of control information. With RRC signaling, information on PDCCH and a CQI table that is referred to are associated with each other, and the CQI table that is referred to is determined based on information relating to the PDCCH. Thus, the CQI table that is referred to is selected at high speed. Furthermore, information relating to control information is control information that is included in the PDCCH or an ePDCCH. Furthermore, the information relating to the control information is a type of search space of the PDCCH or the ePDCCH.
Abstract:
A terminal device receives a frequency resource allocation for data transmission configured of a plurality of subframes and notified from a base station device, the terminal device being provided with an orthogonal sequence generation unit that generates an orthogonal sequence to be applied to a reference signal, in accordance with the number of the plurality of subframes allocated.
Abstract:
In M2M communication, data transmission is performed 4 msec after control information for dynamic scheduling is received from a base station apparatus, and the data transmission that needs immediacy has more overhead. In a case where a transmission apparatus performs data transmission to a reception apparatus, there are a first transmission mode in which a data signal based on a transmission parameter included in the received control information is transmitted, and a second transmission mode in which the control signal information is not received, and the data signal is transmitted without the reception apparatus being notified of a transmission timing of the data signal. In a case where transmission of an SR is possible and in a case where data communication is possible with the first transmission mode and the second transmission mode, the transmission apparatus configures different transmission powers in accordance with the transmission modes.
Abstract:
There has been a problem that a time period between transmission of a synchronization signal and the next transmission thereof may become longer depending on a usage state of an unlicensed band and a terminal apparatus requires a long time to measure receive power of signals from a plurality of base station apparatuses that perform communication in the unlicensed band. A base station apparatus that communicates with a terminal apparatus in a second frequency band different from a first frequency band that is able to be used exclusively includes: a DL signal generation unit that generates a signal to be transmitted to the terminal apparatus; a radio transmission unit that transmits the signal; and a connected terminal management unit that receives information about a plurality of subframes in which a signal is able to be transmitted to the terminal apparatus from another base station apparatus that communicates with the terminal apparatus in the first frequency band. The DL signal generation unit generates a subframe constituted by a synchronization signal and a reference signal, and the radio transmission unit transmits the signal with at least one of subframes included in the information about the plurality of subframes.
Abstract:
In an LTE-A system, there is a problem that it is difficult to perform stable communication in a case where there is a time when another system occupies an unlicensed band being used. There is provided a base station apparatus that communicates with a terminal device in a second frequency band different from a first frequency band capable of being used as a dedicated frequency band. The base station apparatus includes: a wireless transmission unit that transmits data or control information to the terminal device; and a wireless reception unit that receives data or control information transmitted from the terminal device. The wireless transmission unit transmits data to the terminal device, and the wireless reception unit performs a process of receiving ACK/NACK transmitted from the terminal device in a subframe of an initial uplink after communication of another system is ended in a case where the other system performs the communication in the second frequency band at a reception timing of the ACK/NACK of the data transmission.
Abstract:
There are provided a base station apparatus, a terminal apparatus, and a communication method which are capable of realizing a LTE-A system with improved throughput by performing a CA technology including an unlicensed band while suppressing interference from an existing system. A base station apparatus according to the present invention is a base station apparatus which is included in a communication system that applies a communication scheme applied to a first frequency band capable of being used as a dedicated frequency band to a second frequency band different from the first frequency band and is capable of communicating with a terminal apparatus by using the second frequency band and the second frequency band. The base station apparatus synchronizes a frame number of a frame of a first signal transmitted using the first frequency band with a frame number of a frame of a second signal irrespective of whether or not the second signal transmitted using the second frequency band is transmitted.