Controller and transmission and reception method for radio communications in a transceiver for radio communications

• US 20060209746A1
• Filed: 02/07/2006
• Published: 09/21/2006
• Est. Priority Date: 02/09/2005
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Oda, Yasuhiro, Yoshino, Hitoshi, Asai, Takahiro, Sugiyama, Takatoshi
• Granted Patent: US 7,616,554 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 48/18 Selecting a network or a communication service
• CPC Class Codes: H04W 52/245 taking into account received signal strength
• CPC Class Codes: H04W 52/246 where the output power of a terminal is based on a path parameter calculated in said terminal

Abstract

A controller in a transceiver for radio communications in which the same frequency is shared between multiple communications systems is disclosed that includes: a cyclic autocorrelation value calculation part configured to calculate the cyclic autocorrelation value of a first one of the communications systems from a received signal; and a data transmission authorization part configured to determine whether to authorize data transmission in a second one of the communications systems based on the calculated cyclic autocorrelation value of the first one of the communications systems.

Claims

1. A controller in a transceiver for radio communications in which a same frequency is shared between a plurality of communications systems, comprising:

a cyclic autocorrelation value calculation part configured to calculate a cyclic autocorrelation value of a first one of the communications systems from a received signal; and

a data transmission authorization part configured to determine whether to authorize data transmission in a second one of the communications systems based on the calculated cyclic autocorrelation value of the first one of the communications systems.

2. The controller as claimed in claim 1, wherein the cyclic autocorrelation value calculation part calculates the cyclic autocorrelation value of the first one of the communications systems when a level of the received signal is lower than a threshold.

3. The controller as claimed in claim 1, further comprising:

a reception level measurement part configured to measure a level of the received signal,

wherein the data transmission authorization part determines whether to authorize the data transmission in the second one of the communications systems based on at least one of the measured level of the received signal and the calculated cyclic autocorrelation value of the first one of the communications systems.

4. The controller as claimed in claim 3, further comprising:

a LOS/NLOS estimation part configured to estimate whether a transmitter of the first one of the communications systems is in a LOS environment or in an NLOS environment; and

a distance estimation part configured to estimate a distance from the transmitter of the first one of the communications systems to the transceiver for the radio communications using a result of the estimation of the LOS/NLOS estimation part and the measured level of the received signal,

wherein the data transmission authorization part estimates whether the transceiver for the radio communications is within a service area of the first one of the communications systems by comparing the distance estimated in the distance estimation part and the service area of the first one of the communications systems, and determines whether to authorize the data transmission in the second one of the communications systems based on a result of the estimation and the calculated cyclic autocorrelation value of the first one of the communications systems.

5. The controller as claimed in claim 1, further comprising:

a data transmission power determination part configured to control transmission power of the data transmission in the second one of the communications systems based on the calculated cyclic autocorrelation value of the first one of the communications systems.

6. The controller as claimed in claim 5, further comprising:

a LOS/NLOS estimation part configured to estimate whether a transmitter of the first one of the communications systems is in a LOS environment or in an NLOS environment; and

a distance estimation part configured to estimate a distance from the transmitter of the first one of the communications systems to the transceiver for the radio communications using a result of the estimation of the LOS/NLOS estimation part and the measured level of the received signal,

wherein the data transmission authorization part estimates whether the transceiver for the radio communications is within a service area of the first one of the communications systems by comparing the distance estimated in the distance estimation part and the service area of the first one of the communications systems, and determines whether to authorize the data transmission in the second one of the communications systems based on a result of the estimation and the calculated cyclic autocorrelation value of the first one of the communications systems.

7. The controller as claimed in claim 6, wherein the data transmission power determination part controls the transmission power of the data transmission in the second one of the communications systems based on the distance estimated in the distance estimation part and the calculated cyclic autocorrelation value of the first one of the communications systems.

8. The controller as claimed in claim 1, wherein the data transmission authorization part determines whether to authorize the data transmission in the second one of the communications systems based on a result of a chi-square test using the calculated cyclic autocorrelation value of the first one of the communications systems.

9. The controller as claimed in claim 1, wherein the cyclic autocorrelation value is obtained by determining a correlation between an original signal and a signal in which the original signal is frequency-shifted.

10. A radio communications transmission and reception method in a transceiver for radio communications in which a same frequency is shared between a plurality of communications systems, the radio communications transmission and reception method comprising the steps of:

(a) calculating a cyclic autocorrelation value of a first one of the communications systems from a received signal;

(b) determining whether to authorize data transmission in a second one of the communications systems based on the calculated cyclic autocorrelation value of the first one of the communications systems; and

(c) performing the data transmission based on a determination in said step (b) that the data transmission should be authorized.