RADIO COMMUNICATION SYSTEM, TERMINAL APPARATUS, AND RADIO COMMUNICATION METHOD IN THE RADIO COMMUNICATION SYSTEM

• US 20120320833A1
• Filed: 08/24/2012
• Published: 12/20/2012
• Est. Priority Date: 03/05/2010
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Ode, Takayoshi, Yamamoto, Akihiro
• Granted Patent: US 9,219,588 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: H04J 11/0069 Cell search, i.e. determining cell identity [cell-ID] design of multiplexing codes H04J13/00; processing access restriction or access information H04W48/16; discovery of network devices for network data management H04W8/005; sounding signals for channel estimation H04L25/0226; structure of reference signals in multicarrier modulation systems H04L27/2613; frame, time or carrier synchronisation in multicarrier modulation systems H04L27/2655
• CPC Class Codes: H04L 27/2655 Synchronisation arrangements
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04W 56/00 Synchronisation arrangements

Abstract

A radio communication system, including: a base station apparatus; and a terminal apparatus, wherein the base station apparatus and the terminal apparatus transmits to or receives from the terminal apparatus and the base station apparatus respectively a radio signal by using a plurality of frequency bands as a transmission frequency or a reception frequency, the base station apparatus includes a transmission unit which transmits a synchronization signal or a reference signal in each frequency band of the plurality of frequency bands, and the terminal apparatus includes a synchronization control unit which selects at least one synchronization signal or reference signal from the plurality of synchronization signals or reference signals transmitted from the base station apparatus and performs synchronization control based on the selected synchronization signal or reference signal.

Claims

1. A radio communication system, comprising:

a base station apparatus; and

a terminal apparatus, wherein

the base station apparatus and the terminal apparatus transmits to or receives from the terminal apparatus and the base station apparatus respectively a radio signal by using a plurality of frequency bands as a transmission frequency or a reception frequency,

the base station apparatus includes a transmission unit which transmits a synchronization signal or a reference signal in each frequency band of the plurality of frequency bands, and

the terminal apparatus includes a synchronization control unit which selects at least one synchronization signal or reference signal from the plurality of synchronization signals or reference signals transmitted from the base station apparatus and performs synchronization control based on the selected synchronization signal or reference signal.

2. The radio communication system according to claim 1, wherein the synchronization control unit selects the synchronization signal or the reference signal with the lowest frequency out of the plurality of synchronization signals or reference signals.

3. The radio communication system according to claim 1, wherein the synchronization control unit selects the synchronization signal or the reference signal with the highest frequency out of the plurality of synchronization signals or reference signals.

4. The radio communication system according to claim 1, wherein the synchronization control unit selects the synchronization signal or the reference signal with a frequency which is the closest to a central frequency of an aggregated frequency band out of the plurality of synchronization signals or reference signals.

5. The radio communication system according to claim 1, wherein the synchronization control unit selects at least the one synchronization signal and the one reference signal, performs a first synchronization by using the selected synchronization signal, and then performs a second synchronization by using the selected reference signal.

6. The radio communication system according to claim 1, wherein the terminal apparatus further includes a setting control unit which controls the terminal apparatus to transmit or receive the radio signal by using the plurality of frequency bands as the transmission frequency or the reception frequency.

7. The radio communication system according to claim 1, wherein the synchronization signal or the reference signal is a synchronization signal or a reference signal which is different for each frequency band in the plurality of frequency bands respectively.

8. The radio communication system according to claim 1, wherein

the transmission unit transmits the synchronization signal or the reference signal for each frequency band in the plurality of frequency bands included in a reduced frequency bandwidth, when the transmission unit transmits or receives the radio signal by using the reduced frequency bandwidth reduced the plurality of frequency bandwidths, and

the synchronization control unit selects at least the one synchronization signal or the one reference signal out of the plurality of synchronization signals or reference signals, and performs synchronization control.

9. The radio communication system according to claim 1, wherein a first frequency band and a second frequency band out of the plurality of frequency bands belong to different frequency band.

10. The radio communication system according to claim 1, wherein a third frequency band and a fourth frequency band out of the plurality of frequency bands belong to the same frequency band.

11. The radio communication system according to claim 1, wherein

the terminal apparatus further includes a radio communication unit which transmits or receives the radio signal, and

the setting control unit controls the radio communication unit to transmit or receive the radio signal by using the aggregated frequency band as the transmission frequency or the reception frequency.

12. The radio communication system according to claim 7, wherein a signal sequence of the synchronization signal or the reference signal is different for each frequency band in the plurality of frequency bands.

13. The radio communication system according to claim 7, wherein a frequency of the reference signal or the synchronization signal matches a central frequency of each frequency band in the plurality of frequency bands.

14. The radio communication system according to claim 5, wherein the first synchronization is slot timing phase synchronization, and the second synchronization is symbol timing phase synchronization.

15. The radio communication system according to claim 5, wherein the first synchronization is frequency synchronization and the second synchronization is phase synchronization.

16. A terminal apparatus for transmitting to or receiving from a base station apparatus a radio signal by using a plurality of frequency bands as a transmission frequency or a reception frequency, the terminal apparatus comprising:

a reception unit which receives a synchronization signal or a reference signal transmitted from the base station apparatus in each frequency band of the plurality of frequency bands; and

a synchronization control unit which selects at least one synchronization signal or one reference signal out of the plurality of synchronization signals or reference signals and performs synchronization control based on the selected synchronization signal or reference signal.

17. A radio communication method in a radio communication system for transmitting or receiving between a base station apparatus and a terminal apparatus a radio signal by using a plurality of frequency band as a transmission frequency or a reception frequency, the method comprising:

transmitting a synchronization signal or a reference signal in each frequency band of the plurality of frequency bands, by the base station apparatus; and

selecting at least one synchronization signal or one reference signal out of the plurality of synchronization signals or reference signals transmitted from the base station apparatus, and performing synchronization control based on the selected synchronization signal or reference signal.