Communication terminal device, cellular radio communication system, and information communication method

• US 6,411,662 B1
• Filed: 10/26/1998
• Issued: 06/25/2002
• Est. Priority Date: 10/31/1997
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Sakoda, Kazuyuki, Suzuki, Mitsuhiro
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): Liu, Shuwang
• Application Number:
  US09/179,263
• Time in Patent Office: 1,338 Days
• Field of Search: 370/331, 370/332, 370/330, 370/436, 370/343, 455/436, 455/437, 375/227, 375/279, 375/324, 375/340, 375/260
• US Class Current: 375/340
• CPC Class Codes: H04L 1/20 using signal quality detector
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

The present invention relates to a communication terminal device, a cellular radio communication system, and an information communication method, and measures the reception conditions of control information at a higher degree of accuracy. The present invention can measure the reception conditions S10 from the control information S_CCH at a higher degree of accuracy by receiving a transmission signal S5 of the information symbol groups composed of the control information S_CCH transmitted through a predetermined frequency channel CCH, demodulating the reception signal S6 to extract noise components (S15, S20) separated from signal components by comparing the control information S_CCH with reference information S_ref used as a reference for comparison, and measuring the reception condition S10 of only the signal components S33 of the transmission signal S5 based on the noise components (S15, S20).

Claims

1. A communication terminal device for receiving a transmission signal including information symbol groups which are generated by sorting information bits into predetermined information units in a transmission device, said communication terminal device comprising:

a reception device configured to receive said information symbol groups of control information transmitted through a predetermined frequency channel, said frequency channel including plural subcarriers allocated to one user,

a demodulator configured to demodulate the reception signal to extract said control information,

a reference storage device configured to store reference information used as a reference for comparison to identify said control information,

a noise component extraction device configured to compare said control information with said reference information to extract noise components from signal components of said control information, and

a reception condition measurement device configured to measure the reception condition of said transmission signal based on said noise components extracted by said noise component extraction means.

2. The communication terminal device according to claim 1, further comprising:

a selection means for selecting an appropriate transmission device to couple said communication terminal device and a communication line, from among a plurality of transmission devices, based on said reception condition measured by said reception condition measurement device.

3. The communication terminal device according to claim 1, wherein:

said noise component extraction device is configured to extract phase revolution components of said received information symbol groups with respect to the phase of said reference information.

4. The communication terminal device according to claim 1, wherein:

said reception device is configured to receive said transmission signal synchronously at a predetermined reception timing, said transmission signal including said information symbol groups of user information and said information symbol groups of said control information and transmitted at a predetermined time-divisional transmission timing by said transmission device through said frequency channel, and is configured to extract said user information and said control information through time-division technology.

5. The communication terminal device according to claim 1, further comprising:

means for receiving at the receiving end said transmission signal, which is generated by performing a differential modulation operation on said information symbol groups and is transmitted in said transmission device, means for extracting said information symbol groups after performing a differential demodulation operation on said reception signal, and means for separating and extracting said user information and said control information from said information symbol groups.

6. The communication terminal device according to claim 1, wherein:

said reception device is configured to change a frequency channel for reception according to said frequency channel when said frequency channel used for signal transmission is changed for each of said information symbol groups in said transmission device.

7. The communication terminal device according to claim 1, wherein:

said information symbol groups include a control channel signal transmitted over a period longer than one time slot.

8. The communication terminal device according to claim 1, further comprising:

power calculation means for calculating the power of signal components of said control information, wherein

said power calculation means calculates an average by performing several measurements of said power for each of plural frequency channels, the plural frequency channels including the preselected frequency channel, and said communication terminal device notifies the originating transmission device of said average.

9. The communication terminal device according to claim 3, further comprising:

means for measuring a reception timing difference of the reception signal based on said phase revolution components, and means for synchronizing the transmission/reception timing with said transmission device based on said reception timing difference.

10. A communication terminal device for receiving a transmission signal including information symbol groups which are generated by sorting information bits into predetermined information units in a transmission device, said communication terminal device comprising:

a reception device configured to receive said information symbol groups of control information transmitted through a predetermined frequency channel, said frequency channel including plural subcarriers allocated to one user,

a demodulator configured to demodulate the reception signal to extract said control information,

a reference storage device configured to store reference information used as a reference for comparison to identify said control information,

a correlation value calculation device configured to calculate a correlation value by comparing said control information with said reference information, and

a reception condition measurement device configured to measure the reception condition of said transmission signal based on said correlation value calculated by said correlation value calculation means.

11. The communication terminal device according to claim 10, further comprising:

a selection means for selecting an appropriate transmission device to couple said communication terminal device and a communication line, from among a plurality of said transmission devices, based on said reception condition measured by said reception condition measurement means.

12. A cellular radio communication system comprising:

a base station which has a transmission device configured to transmit a transmission signal including information symbol groups generated by sorting information bits into predetermined information units and which is provided in each of a plurality of cells formed by dividing a predetermined communication area into cells of a desired size, and

a mobile station comprising

a reception device configured to receive said information symbol groups of control information transmitted through a predetermined frequency channel, said frequency channel including plural subcarriers allocated to one user,

a demodulator configured to demodulate the reception signal to extract said control information,

a reference storage device configured to store reference information used as a reference for comparison to identify said control information,

a noise component extraction device configured to separate and extract noise components from signal components of said control information by comparing said control information with said reference information, and

a reception condition measurement device configured to measure the reception condition of said transmission signal based on said noise components extracted by said noise component extraction means.

13. The cellular radio communication system according to claim 12, further comprising:

a selection means for selecting an appropriate base station to connect said mobile station and a communication line, from among a plurality of said base stations, based on said reception condition measured by said reception condition measurement device.

14. The cellular radio communication system according to claim 12, wherein:

said noise component extraction device is configured to extract phase revolution components of said received information symbol groups with respect to the phase of said reference information.

15. The cellular radio communication system according to claim 12, wherein:

said base station is configured to transmit said transmission signal at a predetermined time-divisional transmission timing through said frequency channel, said transmission signal including said information symbol groups of user information and said information symbol groups of said control information, and said mobile station is configured to receive said transmission signal synchronously at a predetermined reception timing and to extract said user information and said control information through time-division technology.

16. The cellular radio communication system according to claim 12, further comprising:

means for transmitting said transmission signal by performing a differential modulation operation on said information symbol groups in said base station, means for receiving said transmission signal in said mobile station, means for extracting said information symbol groups by performing a differential demodulation operation on the reception signal, and means for separating and extracting said user information and said control information from said information symbol groups.

17. The cellular radio communication system according to claim 12, wherein:

said mobile station is configured to change a frequency channel for reception when said frequency channel used for signal transmission is changed for each of said information symbol groups in said base station.

18. The cellular radio communication system according to claim 12, wherein:

said mobile station is configured to receive said information symbol groups transmitted by said base station through multicarrier modulation technology.

19. The cellular radio communication system according to claim 12, further comprising:

a power calculation means for calculating the power of signal components of said control information, wherein said power calculation means calculates an average by performing several measurements of said power for each of plural frequency channels, and

means for notifying the base station of said average.

20. The cellular radio communication system according to claim 14, further comprising:

means for measuring a reception timing difference of the reception signal in said mobile station based on said phase revolution components, and means for synchronizing the transmission/reception timing with said base station based on said reception timing difference.

21. A cellular radio communication system comprising:

a base station which has a transmission device configured to transmit a transmission signal including information symbol groups generated by sorting information bits into predetermined information units and which is provided in each of a plurality of cells formed by dividing a predetermined communication area into cells of a desired size, and

a mobile station comprising;

a reception device configured to receive said information symbol groups of control information transmitted through a predetermined frequency channel, said frequency channel including plural subcarriers allocated to one user,

a demodulator configured to demodulate the reception signal to extract said control information,

a reference storage device configured to store reference information used as a reference for comparison to identify said control information,

a correlation value calculation device configured to calculate a correlation value by comparing said control information with said reference information, and

a reception condition measurement device configured to measure the reception condition of said transmission signal based on said correlation value calculated by said correlation value calculation means.

22. The cellular radio communication system according to claim 21, further comprising:

selection means for selecting an appropriate base station to connect said mobile station and a communication line, from among a plurality of said base stations, based on said reception condition measured by said reception condition measurement device.

23. An information communication method for receiving at the receiving end a transmission signal including information symbol groups which are generated by sorting information bits into predetermined information units at the transmitting end, comprising:

receiving at said receiving end said information symbol groups of control information transmitted from said transmitting end through a predetermined frequency channel, said frequency channel including plural subcarriers allocated to one user,

demodulating the reception signal to extract said control information,

separating and extracting noise components from signal components of said control information by comparing said control information with reference information used as a reference for comparison to identify said control information, and

measuring the reception condition of said transmission signal based on said extracted noise components.

24. The information communication method according to claim 23, further comprising:

selecting an appropriate transmitting end to connect said receiving end and a communication line, from among a plurality of said transmitting ends, based on said measured reception condition.

25. The information communication method according to claim 23, wherein said noise extraction step comprises extracting phase revolution components of said received information symbol groups with respect to the phase of said reference information at said receiving end.

26. The information communication method according to claim 23, further comprising:

transmitting at said transmitting end said transmission signal at a predetermined time-divisional transmission timing through said frequency channel, said transmission signal including said information symbol groups of user information and said information symbol groups of said control information,

receiving said transmission signal synchronously at said receiving end at a predetermined reception timing, and

extracting said user information and said control information through time-division technology.

27. The information communication method according to claim 23, further comprising:

transmitting said transmission signal at said transmitting end, said transmission signal generated by performing a differential modulation operation on said information symbol groups, receiving said transmission signal at said receiving end, and

extracting said information symbol groups by performing a differential demodulation operation on the reception signal.

28. The information communication method according to claim 23, further comprising:

changing at said receiving end a frequency channel for reception according to said frequency channel when said frequency channel used for signal transmission is changed for each of said information symbol groups at said transmitting end.

29. The information communication method according to claim 23, further comprising:

demodulating at said receiving end said information symbol groups transmitted by said transmitting end through multicarrier modulation technology.

30. The information communication method according to claim 23, further comprising:

calculating the power of signal components of said control information, including calculating an average by performing several measurements of said power for each of said frequency channel,

wherein said method further comprises notifying said transmitting end which transmits said transmission signal of said average.

31. The information communication method according to claim 25, further comprising:

measuring a reception timing difference of the reception signal at said receiving end based on said phase revolution components, and

synchronizing the transmission/reception timing with said transmitting end based on said reception timing difference.

32. An information communication method for receiving at a receiving end a transmission signal including information symbol groups which are generated by sorting information bits into predetermined information units at the transmitting end, comprising:

receiving at said receiving end said information symbol groups of control information transmitted from said transmitting end through a predetermined frequency channel, said frequency channel including plural subcarriers allocated to one user,

demodulating the reception signal to extract said control information,

calculating a correlation value by comparing said control information with reference information used as a reference for comparison to identify said control information, and

measuring the reception condition of said transmission signal based on said correlation value.

33. The information communication method according to claim 32, further comprising:

selecting an appropriate transmitting end to connect said receiving end and a communication line, from among a plurality of said transmitting ends, based on said measured reception condition.