Abstract: The present invention provides a single carrier/DS-CDMA packet transmission method wherein a predetermined time slot is assigned to reservation demand packet transmission in regard to a spreading code, and the reservation demand packet and data packets are time-multiplexed for transmission. An uplink packet transmission method in a multi-carrier/DS-CDMA mobile communication system is also provided, wherein frames are set up in each communication channel of a subcarrier, time slots which are time-segments of the frames are set up further, and a mobile station spreads a packet to be transmitted by a spreading code and the information signal is transmitted to a base station in a predetermined time slot.

Abstract: The present invention provides a single carrier/DS-CDMA packet transmission method wherein a predetermined time slot is assigned to reservation demand packet transmission in regard to a spreading code, and the reservation demand packet and data packets are time-multiplexed for transmission. An uplink packet transmission method in a multi-carrier/DS-CDMA mobile communication system is also provided, wherein frames are set up in each communication channel of a subcarrier, time slots which are time-segments of the frames are set up further, and a mobile station spreads a packet to be transmitted by a spreading code and the information signal is transmitted to a base station in a predetermined time slot.

Abstract: The present invention provides a single carrier/DS-CDMA packet transmission method wherein a predetermined time slot is assigned to reservation demand packet transmission in regard to a spreading code, and the reservation demand packet and data packets are time-multiplexed for transmission. An uplink packet transmission method in a multi-carrier/DS-CDMA mobile communication system is also provided, wherein frames are set up in each communication channel of a subcarrier, time slots which are time-segments of the frames are set up further, and a mobile station spreads a packet to be transmitted by a spreading code and the information signal is transmitted to a base station in a predetermined time slot.

Abstract: The present invention provides a single carrier/DS-CDMA packet transmission method wherein a predetermined time slot is assigned to reservation demand packet transmission in regard to a spreading code, and the reservation demand packet and data packets are time-multiplexed for transmission. An uplink packet transmission method in a multi-carrier/DS-CDMA mobile communication system is also provided, wherein frames are set up in each communication channel of a subcarrier, time slots which are time-segments of the frames are set up further, and a mobile station spreads a packet to be transmitted by a spreading code and the information signal is transmitted to a base station in a predetermined time slot.

Abstract: The object of the present invention to provide a directional beam communication system whereby the beam width of a directional beam to be transmitted is reduced by sharing an array antenna among a plurality of adjacent sectors so as to increase the interference suppression effect. The directional beam communication system is configured to communicate with a mobile station MS located in a service area formed by a plurality of sectors S1 and S2 using a directional beam which is transmitted by an array antenna A including a plurality of antenna elements a. The array antenna A for transmitting the directional beam is shared among at least two adjacent sectors S1 and S2.

Abstract: A method for connecting the radio link between a mobile station and a base station is provided to improve quality of received signals at the base station and the mobile station. A radio network controller (RNC) monitors the difference between the reception power of signals from the source base station BS1 and the destination base station BS2. If the base station BS2 is incapable of directional beam signal transmission and reception, and when the reception power difference becomes smaller than a first handover threshold, the radio network controller adds the base station BS2 as a radio link connection destination of the mobile station. If the base station BS2 is capable of directional beam signal transmission and reception, and when the reception power difference becomes smaller than a second handover threshold, which is larger than the first handover threshold, the radio network controller adds the base station BS2 as a radio link connection destination of the mobile station.

Abstract: The object of the present invention is to improve the accuracy of channel estimation and increase downlink capacity when a base station transmits an individual channel using directional beams. The base station 10 according to the present invention comprises an individual channel transmitter 15 configured to transmit an individual channel into which pilot symbols are inserted; and an individual channel format creator 14 configured to create a format of the individual channel. The individual channel format creator 14 changes between a format of an individual channel which is to be transmitted using directional beams and a format of an individual channel which is to be transmitted using non-directional beams.

Abstract: A base station is configured to transmit a downlink signal to a mobile station located in a sector managed by the base station. The downlink signal is spread using a scrambling code. The base station has a monitor configured to monitor a change of a reception condition of an uplink common channel of the mobile station in the sector, a DOA estimator configured to estimate a direction of arrival of an uplink signal transmitted from the mobile station, in response to the change, an area border setter configured to separate the sector into a plurality of areas, by setting an area border in the sector in accordance with the estimated direction, a scrambling code assigner configured to assign a different scrambling code to each of the separated areas and a spreader configured to spread the downlink signal using the assigned scrambling code in each of the separated areas.

Abstract: A base station comprises a directional antenna configured to transmit a directional beam to a mobile station, an omnidirectional antenna configured to transmit an omnidirectional beam to the mobile station, and an antenna controller configured to determine whether or not the mobile station is capable of receiving the directional beam, and select the directional antenna as an antenna for transmitting individual data in a case of being capable of receiving the directional beam, or select the omnidirectional antenna as an antenna for transmitting the individual data in a case of being incapable of receiving the directional beam.

Abstract: The object of the present invention is to avoid disconnection of a radio link between the radio base station and the mobile station even when the mobile station moves while transmitting no up signals in a case where the radio base station transmits the directional beam. The radio base station according to the present invention comprises an array antenna 11 to transmit/receive the directional beam, an transceiver 12 to receive an up signal from a mobile station 2 and to generate a directional beam pattern for each mobile station according to an antenna weight, a up signal interval measurer 13 to measure elapsed time from reception of the up signal, and a antenna weight generator 15 to change the antenna weight based on a result of measuring by the up signal interval measurer 13.

Abstract: A DS-CDMA transmission method capable of improving the accuracy of channel estimation using pilot symbols by eliminating cross-correlation between pilot symbols inserted into code channels in CDMA multiplexing carrying out fast signal transmission. In each frame assembler, the pilot symbols, which are used for channel estimation for coherent detection, are inserted into coded information data on code channels at fixed intervals, and then the data is modulated by the modulator. The modulated data symbols in each code channel from the modulator are spread by the spreading modulator, the pilot symbols are spread using a spreading code, whereas the information symbols are spread using different spreading codes assigned to respective code channels. The spread signals of the code channels are summed up by the adder to be transmitted.

Abstract: The object of the present invention to provide a directional beam communication system whereby the beam width of a directional beam to be transmitted is reduced by sharing an array antenna among a plurality of adjacent sectors so as to increase the interference suppression effect. The directional beam communication system is configured to communicate with a mobile station MS located in a service area formed by a plurality of sectors S1 and S2 using a directional beam which is transmitted by an array antenna A including a plurality of antenna elements a. The array antenna A for transmitting the directional beam is shared among at least two adjacent sectors S1 and S2.

Abstract: A base station is configured to transmit a downlink signal to a mobile station located in a sector managed by the base station. The down link signal is spread using a scrambling code. The base station has a monitor configured to monitor a change of a reception condition of an uplink common channel of the mobile station in the sector, a DOA estimator configured to estimate a direction of arrival of an uplink signal transmitted from the mobile station, in response to the change, an area border setter configured to separate the sector into a plurality of areas, by setting an area border in the sector in accordance with the estimated direction, a scrambling code assigner configured to assign a different scrambling code to each of the separated areas and a spreader configured to spread the downlink signal using the assigned scrambling code in each of the separated areas.

Abstract: The object of the present invention is to avoid disconnection of a radio link between the radio base station and the mobile station even when the mobile station moves while transmitting no up signals in a case where the radio base station transmits the directional beam. The radio base station according to the present invention comprises an array antenna 11 to transmit/receive the directional beam, an transceiver 12 to receive an up signal from a mobile station 2 and to generate a directional beam pattern for each mobile station according to an antenna weight, a up signal interval measurer 13 to measure elapsed time from reception of the up signal, and a antenna weight generator 15 to change the antenna weight based on a result of measuring by the up signal interval measurer 13.

Abstract: A base station comprises a directional antenna configured to transmit a directional beam to a mobile station, an omnidirectional antenna configured to transmit an omnidirectional beam to the mobile station, and an antenna controller configured to determine whether or not the mobile station is capable of receiving the directional beam, and select the directional antenna as an antenna for transmitting individual data in a case of being capable of receiving the directional beam, or select the omnidirectional antenna as an antenna for transmitting the individual data in a case of being incapable of receiving the directional beam.

Abstract: The object of the present invention is to improve the accuracy of channel estimation and increase downlink capacity when a base station transmits an individual channel using directional beams. The base station 10 according to the present invention comprises an individual channel transmitter 15 configured to transmit an individual channel into which pilot symbols are inserted; and an individual channel format creator 14 configured to create a format of the individual channel. The individual channel format creator 14 changes between a format of an individual channel which is to be transmitted using directional beams and a format of an individual channel which is to be transmitted using non-directional beams.

Abstract: A method for connecting the radio link between a mobile station and a base station is provided to improve quality of received signals at the base station and the mobile station. A radio network controller (RNC) monitors the difference between the reception power of signals from the source base station BS1 and the destination base station BS2. If the base station BS2 is incapable of directional beam signal transmission and reception, and when the reception power difference becomes smaller than a first handover threshold, the radio network controller adds the base station BS2 as a radio link connection destination of the mobile station. If the base station BS2 is capable of directional beam signal transmission and reception, and when the reception power difference becomes smaller than a second handover threshold, which is larger than the first handover threshold, the radio network controller adds the base station BS2 as a radio link connection destination of the mobile station.

Abstract: A DS-CDMA transmission method capable of improving the accuracy of channel estimation using pilot symbols by eliminating cross-correlation between pilot symbols inserted into code channels in CDMA multiplexing carrying out fast signal transmission. In each frame assembler, the pilot symbols, which are used for channel estimation for coherent detection, are inserted into coded information data on code channels at fixed intervals, and then the data is modulated by the modulator. The modulated data symbols in each code channel from the modulator are spread by the spreading modulator, the pilot symbols are spread using a spreading code, whereas the information symbols are spread using different spreading codes assigned to respective code channels. The spread signals of the code channels are summed up by the adder to be transmitted.

Abstract: The present invention provides a single carrier/DS-CDMA packet transmission method wherein a predetermined time slot is assigned to reservation demand packet transmission in regard to a spreading code, and the reservation demand packet and data packets are time-multiplexed for transmission. An uplink packet transmission method in a multi-carrier/DS-CDMA mobile communication system is also provided, wherein frames are set up in each communication channel of a subcarrier, time slots which are time-segments of the frames are set up further, and a mobile station spreads a packet to be transmitted by a spreading code and the information signal is transmitted to a base station in a predetermined time slot.

Abstract: A DS-CDMA transmission method capable of improving the accuracy of channel estimation using pilot symbols by eliminating cross-correlation between pilot symbols inserted into code channels in CDMA multiplexing carrying out fast signal transmission. In each frame assembler, the pilot symbols, which are used for channel estimation for coherent detection, are inserted into coded information data on code channels at fixed intervals, and then the data is modulated by the modulator. The modulated data symbols in each code channel from the modulator are spread by the spreading modulator, the pilot symbols are spread using a spreading code, whereas the information symbols are spread using different spreading codes assigned to respective code channels. The spread signals of the code channels are summed up by the adder to be transmitted.