Communication system and small-cell base station
A deviation of time at which downlink signals synchronously transmitted from a macro-cell base station and a small-cell base station respectively reach a communication terminal apparatus can be made within an allowable range, without being affected by transmission delay in transmission cables of base station and propagation delay in radio transmission paths. The small-cell base station is provided with a radio transceiving section connected with antenna, a radio communication control section, a transmission cable connected with the radio transceiving section and the radio communication control section, and a downlink signal receiving section for receiving downlink signals transmitted from the macro-cell base station and the own base station respectively. The small-cell base station measures a reception-timing difference of downlink signals transmitted from the macro-cell base station and the own base station based on a reception result of the downlink signal, adjusts a transmission timing of downlink signal of the own base station based on the reception-timing difference, and transmits a downlink signal at the adjusted transmission timing.
1. A small-cell base station that is located in a macro cell of a macro-cell base station and synchronously transmits a data to a communication terminal apparatus by matching timing with the macro-cell base station, comprising:
a radio transceiving section connected with an antenna;
a radio communication control section;
a transmission cable connecting the radio transceiving section and the radio communication control section; and
a downlink signal receiving section receives downlink signals transmitted from the macro-cell base station and an own base station respectively, and
wherein the small-cell base station measures a reception-timing difference between downlink signals transmitted from the macro-cell base station and the own base station based on a reception result of the downlink signals, adjusts a transmission timing of downlink signal of the own base station based on the reception-timing difference, and transmits a downlink signal at the adjusted transmission timing,
wherein the downlink signal receiving section:
measures a reception-timing difference between the downlink signals transmitted from the macro-cell base station and the own base station based on the reception result of the downlink signals; and
transmits information on the reception-timing difference to the radio communication control section of the own base station,
wherein the radio communication control section:
receives the information of the reception-timing difference from the downlink signal receiving section of the own base station,
calculates an offset value of the transmission timing of downlink signal of the own base station based on the reception-timing difference;
adjusts the transmission timing of downlink signal of the own base station based on the offset value; and
controls to transmit the downlink signal at the adjusted transmission timing, and
wherein the small-cell base station calculates the offset value of the transmission timing of downlink signal of the own base station based on the reception-timing difference and a cell radius of the own base station.
2. The small-cell base station according to claim 1 ,
wherein the downlink signal receiving section is included in the radio transceiving section, and
wherein the information on the reception-timing difference or the information on the offset value of the transmission timing is transmitted from the radio transceiving section to the radio communication control section via the transmission cable.
3. The small-cell base station according to claim 1 ,
wherein the small-cell base station continuously performs a reception process of the downlink signal and a measurement process of the reception-timing difference.
4. The small-cell base station according to claim 1 ,
wherein the small-cell base station periodically performs a reception process of the downlink signal and a measurement process of the reception-timing difference.
5. A communication system, comprising:
a small-cell base station according to claim 1 , and
a macro-cell base station of a macro cell in which the small-cell base station is located.
6. The small-cell base station according to claim 1 , wherein
the downlink signal receiving section is included in the radio transceiving section, and
wherein the information on the reception-timing difference or the information on the offset value of the transmission timing is transmitted from the radio transceiving section to the radio communication control section via the transmission cable.
7. A small-cell base station that is located in a macro cell of a macro-cell base station and synchronously transmits a data to a communication terminal apparatus by matching timing with the macro-cell base station, comprising:
a radio transceiving section connected with an antenna;
a radio communication control section;
a transmission cable connecting the radio transceiving section and the radio communication control section; and
a downlink signal receiving section receives downlink signals transmitted from the macro-cell base station and an own base station respectively, and
wherein the small-cell base station measures a reception-timing difference between downlink signals transmitted from the macro-cell base station and the own base station based on a reception result of the downlink signals, adjusts a transmission timing of downlink signal of the own base station based on the reception-timing difference, and transmits a downlink signal at the adjusted transmission timing,
wherein the downlink signal receiving section:
measures a reception-timing difference between the downlink signals transmitted from the macro-cell base station and the own base station based on the reception result of the downlink signal;
calculates an offset value of the transmission timing of downlink signal of the own base station based on the reception-timing difference; and
transmits information on the offset value of the transmission timing to the radio communication control section of the own base station,
wherein the radio communication control section:
receives the information on the offset value of the transmission timing from the downlink signal receiving section of the own base station;
adjusts the transmission timing of downlink signal of the own base station based on the offset value; and
controls to transmit the downlink signal at the adjusted transmission timing, and
wherein the small-cell base station calculates the offset value of the transmission timing of downlink signal of the own base station based on the reception-timing difference and a cell radius of the own base station.
8. The small-cell base station according to claim 7 , wherein
the downlink signal receiving section is included in the radio transceiving section, and
wherein the information on the reception-timing difference or the information on the offset value of the transmission timing is transmitted from the radio transceiving section to the radio communication control section via the transmission cable.
9. The small-cell base station according to claim 7 ,
wherein the small-cell base station continuously performs a reception process of the downlink signal and a measurement process of the reception-timing difference.
10. The small-cell base station according to claim 7 ,
wherein the small-cell base station periodically performs a reception process of the downlink signal and a measurement process of the reception-timing difference.
11. A communication system, comprising:
a small-cell base station according to claim 7 , and
a macro-cell base station of a macro cell in which the small-cell base station is located.