Mobile communication systems, mobile communication methods, base stations, mobile stations, and signal transmission methods in the mobile communication systems

Abstract

A mobile station is configured to measure receiving qualities of respective signals from a first antenna and a second antenna of a base station (S 3 , S 5 ), store the results of the measurement, and request the base station to retransmit a signal from an antenna with a higher receiving quality, based on the stored measurement results, when an error is detected in received data thereafter (S 10 , S 11 , S 12 ). The base station retransmits the data, using the antenna with the higher receiving quality (i.e., a base station antenna to yield the higher receiving quality at the mobile station) (S 15 ). In another aspect, the mobile station measures a receiving quality of a signal and notifies the base station of the receiving quality. The base station selects a radio channel adapted to a receiving quality on the basis of the measurement result and transmits a signal, using the radio channel.

1 . A mobile station configured to perform signal transmission/reception control including signal retransmission control based on an automatic repeat request, with a base station equipped with a plurality of antennas and configured to transmit a signal on the basis of a signal transmission request from at least one antenna out of the plurality of antennas, said mobile station comprising: 
 a quality measuring unit configured to measure receiving qualities of signals transmitted from the plurality of antennas of said base station; and    a transmitter configured to transmit an antenna use request to said base station that a signal should be transmitted from at least one antenna out of said plurality of antennas, based on the receiving qualities of the signals from the respective antennas obtained by measurement.    
   
   
       2 . A mobile station configured to perform signal transmission/reception control including multicast signal retransmission control based on an automatic repeat request, with a base station equipped with a plurality of antennas and configured to transmit a multicast signal on the basis of a signal transmission request from at least one antenna out of the plurality of antennas, said mobile station comprising: 
 a quality measuring unit configured to measure receiving qualities of signals transmitted from the plurality of antennas of said base station; and    a transmitter configured to transmit an antenna use request to said base station that a multicast signal should be transmitted from at least one antenna out of said plurality of antennas, based on the receiving qualities of the signals from the respective antennas obtained by measurement.    
   
   
       3 . The mobile station according to  claim 1 , wherein said quality measuring unit measures said receiving quality by using a synchronization signal, a signal of annunciation information, an individual signal to the mobile station, a multicast signal, or a combination of two or more out of these signals, transmitted from at least one antenna of said base station.  
   
   
       4 . The mobile station according to  claim 1 , wherein said receiving quality is a received power, a value obtained by dividing a carrier power by the sum of an interference power and a noise power, a value obtained by dividing a signal power by the sum of an interference power and a noise power, an error rate, a likelihood obtained in decoding of error correction code, a C/N ratio, an S/N ratio, a correlation value obtained by despreading of spreading code, or a combination of two or more out of these.  
   
   
       5 . A signal transmitting method in a mobile communication system comprising a mobile station and a base station and configured to perform transmission/reception of a signal while sending and receiving an automatic repeat request, said signal transmitting method being carried out as follows in the mobile communication system: 
 measuring at said mobile station a receiving quality of a radio signal transmitted from the base station,    notifying at said mobile station the base station of the receiving quality of the radio signal thus measured, and    transmitting from said base station a signal under a repeat request from said mobile station so as to meet a required receiving quality of the mobile station, based on the receiving quality thus notified of,    wherein when a repeat request for retransmission of a received signal is needed, said mobile station notifies said base station of said repeat request, together with said receiving quality of the radio signal measured.    
   
   
       6 . The signal transmitting method according to  claim 5 , wherein the radio signal transmitted from said base station becomes at least one radio channel.  
   
   
       7 . The signal transmitting method according to  claim 6 , wherein said mobile station uses, as a radio channel for measurement of the receiving quality, an annunciation information channel or an individual channel or a multicast channel or a combination of these, among said at least one radio channel transmitted from said base station.  
   
   
       8 . The signal transmitting method according to  claim 7 , wherein said receiving quality is one selected from at least one of the following: 
 a received power;      C/(I+N)  (Eq. 1)    C: carrier power    I: interference power    N: noise power;      S/(I+N)  (Eq. 2)    S: signal power    I: interference power    N: noise power;      C/N  (Eq. 3)    C: carrier power    N: noise power;      S/N  (Eq. 4)    S: signal power    N: noise power;    an error rate;    a likelihood obtained in decoding of error correction code;    a transmission power value of the base station;    an increase amount or an attenuation amount of the transmission power of the base station.    
   
   
       9 . The signal transmitting method according to  claim 6 , wherein radio channels transmitted and received between said base station and said mobile station are at least one of subcarrier channels, orthogonal subcarrier channels, frequency channels, and frequency channels in different frequency bands.  
   
   
       10 . The signal transmitting method according to  claim 5 , wherein on an occasion of notifying said base station of an acknowledgement of arrival of a received signal, said mobile station notifies the base station of the receiving quality of said at least one radio channel measured.  
   
   
       11 . The signal transmitting method according to  claim 5 , wherein said mobile station notifies the base station of a number of at least one radio channel and a receiving quality of the radio channel, or of only a channel number of a receiving quality within a predetermined range, as the receiving quality of said at least one radio channel measured.  
   
   
       12 . The signal transmitting method according to  claim 5 , wherein said mobile station notifies said base station of a number of at least one radio channel satisfying a required receiving quality, including a radio channel with a maximum receiving quality at said mobile station, together with the receiving quality achieved.  
   
   
       13 . The signal transmitting method according to  claim 5 , wherein said base station determines a radio channel satisfying the required receiving quality at the mobile station on the basis of notification from said mobile station, and 
 the base station transmits a signal under a repeat request from the mobile station, using the radio channel determined.    
   
   
       14 . The signal transmitting method according to  claim 13 , wherein after transmitting the signal under the repeat request from said mobile station, using said determined radio channel, said base station also transmits a signal addressed to the mobile station, using said determined radio channel.  
   
   
       15 . The signal transmitting method according to  claim 13 , wherein, based on the notification from said mobile station, said base station determines a number of a radio channel which satisfies the required receiving quality at the mobile station and through which the signal is transmitted so that a transmission power from the base station becomes a predetermined value, and also determines a transmission power of the radio channel.  
   
   
       16 . The signal transmitting method according to  claim 15 , wherein when said base station transmits an identical multicast signal to a plurality of mobile stations, the base station determines a number of at least one radio channel which satisfies the required receiving quality at each mobile station and through which the multicast signal is transmitted so that a transmission power from the base station becomes a predetermined value, and also determines a transmission power of the radio channel, based on notification from each mobile station.  
   
   
       17 . The signal transmitting method according to  claim 16 , wherein when said base station transmits the identical multicast signal to the plurality of mobile stations, the base station determines a number of a radio channel that can be assumed to have the greatest number of repeat requests from the mobile stations, out of channel numbers with receiving qualities within a predetermined range, notified of by the respective mobile stations.  
   
   
       18 . A mobile communication system comprising: 
 a mobile station, and    a base station and configured to perform transmission/reception of a signal while sending and receiving an automatic repeat request,    wherein said mobile station comprises: a quality measuring unit configured to measure a receiving quality of a radio signal transmitted from the base station; and    a notifying unit configured to notify the base station of the receiving quality of the radio signal thus measured, wherein when a repeat request for retransmission of a received signal is needed, said notifying unit notifies said base station of said repeat request, together with said receiving quality of the radio signal measured, and    said base station comprises: a transmitter configured to transmit a signal under a repeat request from said mobile station so that a required receiving quality is satisfied at the mobile station, based on the receiving quality notified of by the mobile station.    
   
   
       19 . The mobile communication system according to  claim 18 , wherein said quality measuring unit measures a receiving quality of at least one radio channel transmitted from the base station.  
   
   
       20 . The mobile communication system according to  claim 19 , wherein said quality measuring unit uses, as a radio channel for measurement of the receiving quality at said mobile station, one selected from an annunciation information channel, an individual channel, a multicast channel, and a combination of these, among said at least one radio channel transmitted from the base station.  
   
   
       21 . The mobile communication system according to  claim 19 , wherein said receiving quality is one selected from at least one of the following: 
 a received power;      C/(I+N)  (Eq. 1)    C: carrier power    I: interference power    N: noise power;      S/(I+N)  (Eq. 2)    S: signal power    I: interference power    N: noise power;      C/N  (Eq. 3)    C: carrier power    N: noise power;      S/N  (Eq. 4)    S: signal power    N: noise power;    an error rate;    a likelihood obtained in decoding of error correction code;    a transmission power value of the base station; and    an increase amount or an attenuation amount of the transmission power of the base station.    
   
   
       22 . The mobile communication system according to  claim 19 , wherein radio channels transmitted and received between said base station and said mobile station are at least one of subcarrier channels, orthogonal subcarrier channels, frequency channels, and frequency channels in different frequency bands.  
   
   
       23 . The mobile communication system according to  claim 18 , wherein on an occasion of notifying said base station of an acknowledgement of arrival of a received signal, said notifying unit notifies the base station of the receiving quality of said at least one radio channel measured.  
   
   
       24 . The mobile communication system according to  claim 18 , wherein said notifying unit notifies the base station of a number of at least one radio channel and a receiving quality of the radio channel, or of only a channel number of a receiving quality within a predetermined range, as the receiving quality of said at least one radio channel measured.  
   
   
       25 . The mobile communication system according to  claim 18 , wherein said notifying unit notifies said base station of a number of at least one radio channel satisfying a required receiving quality, including a radio channel with a maximum receiving quality at said mobile station, together with the receiving quality achieved.  
   
   
       26 . The mobile communication system according to  claim 18 , wherein said base station comprises: 
 radio channel determining unit configured to determine a radio channel satisfying the required receiving quality at the mobile station on the basis of notification from said mobile station; and    a transmitter configured to transmit a signal under a repeat request from the mobile station, using the radio channel determined by the radio channel determining unit.    
   
   
       27 . The mobile communication system according to  claim 26 , wherein after transmitting the signal under the repeat request from said mobile station, using said determined radio channel, said transmitter in said base station also transmits a signal addressed to the mobile station, using said determined radio channel.  
   
   
       28 . The mobile communication system according to  claim 26 , wherein said base station comprises: first radio channel number unit configured to determine a number of a radio channel which satisfies the required receiving quality at the mobile station and through which the signal is transmitted so that a transmission power from the base station becomes a predetermined value, based on the notification from said mobile station; and first radio channel transmission power determining unit configured to determine a transmission power of the radio channel.  
   
   
       29 . The mobile communication system according to  claim 28 , wherein said base station comprises: 
 second radio channel number determining unit configured to, on an occasion of transmitting an identical multicast signal to a plurality of mobile stations, determine a number of at least one radio channel which satisfies the required receiving quality at each mobile station and through which the multicast signal is transmitted so that a transmission power from the base station becomes a predetermined value, based on notification from each mobile station; and    second radio channel transmission power determining unit configured to determine a transmission power of the radio channel.    
   
   
       30 . The mobile communication system according to  claim 29 , wherein said base station comprises: 
 third radio channel number determining unit configured to, on an occasion of transmitting the identical multicast signal to the plurality of mobile stations, determine a number of a radio channel that can be assumed to have the greatest number of repeat requests from the mobile stations, out of channel numbers with receiving qualities within a predetermined range, notified of by the respective mobile stations.    
   
   
       31 . The mobile communication system according to  claim 18 , wherein said base station comprises: 
 a radio resource determining unit configured to determine a radio resource satisfying the required receiving quality at the mobile station on the basis of notification from said mobile station; and    a transmitter configured to transmit the signal under the repeat request from said mobile station, using the radio resource determined by said radio resource determining unit.    
   
   
       32 . The mobile communication system according to  claim 18 , wherein said transmitter of said base station transmits the signal by using radio resources in decreasing order of the number of repeat requests from the mobile station.  
   
   
       33 . The mobile communication system according to  claim 31 , wherein said radio resource is at least one antenna, directivities of at least one antenna, a radio channel, a transmission path, or either of combinations of these.  
   
   
       34 . A base station in a mobile communication system comprising a mobile station and the base station and configured to perform transmission/reception of a signal while sending and receiving an automatic repeat request, said base station comprising: 
 a transmitter configured to transmit a signal under a repeat request from said mobile station so that a required receiving quality is satisfied at the mobile station, based on a receiving quality notified of by the mobile station wherein said receiver quality is included in the repeat request.    
   
   
       35 . The base station according to  claim 34 , said base station comprising: 
 radio channel determining unit configured to determine a radio channel satisfying the required receiving quality at the mobile station, based on notification from said mobile station; and    said transmitter configured to transmit the signal under the repeat request from the mobile station, using the radio channel determined by the radio channel determining unit.    
   
   
       36 . The base station according to  claim 34 , wherein after transmitting the signal under the repeat request from said mobile station, using said determined radio channel, said transmitter also transmits a signal addressed to the mobile station, using said determined radio channel.  
   
   
       37 . The base station according to  claim 34 , 
 said base station comprising:    first radio channel number determining unit configured to determine a number of a radio channel which satisfies the required receiving quality at the mobile station and through which the signal is transmitted so that a transmission power from the base station becomes a predetermined value, based on notification from said mobile station; and    first radio channel transmission power determining means for determining a transmission power of the radio channel.    
   
   
       38 . The base station according to  claim 34 , 
 said base station comprising:    second radio channel number determining unit configured to, on an occasion of transmitting an identical multicast signal to a plurality of mobile stations, determine a number of at least one radio channel which satisfies the required receiving quality at each mobile station and through which the multicast signal is transmitted so that a transmission power from the base station becomes a predetermined value, based on notification from each mobile station; and second radio channel transmission power determining unit for determining a transmission power of the radio channel.    
   
   
       39 . The base station according to  claim 34 , 
 said base station comprising:    third radio channel number determining unit configured to, on an occasion of transmitting an identical multicast signal to a plurality of mobile stations, determine a number of a radio channel that can be assumed to have the greatest number of repeat requests from the mobile stations, out of channel numbers with receiving qualities within a predetermined range, notified of by the respective mobile stations.    
   
   
       40 . The base station according to  claim 34 , wherein radio channels used between said base station and said mobile station are at least one of subcarrier channels, orthogonal subcarrier channels, frequency channels, and frequency channels in different frequency bands.  
   
   
       41 . A mobile station in a mobile communication system comprising the mobile station and a base station and configured to perform transmission/reception of a signal while sending and receiving an automatic repeat request, 
 said mobile station comprising:    a quality measuring unit configured to measure a receiving quality of a radio signal transmitted from the base station; and    a notifying unit configured to transmit a repeat request together with the receiving quality of the radio signal thus measured to the base station.    
   
   
       42 . The mobile station according to  claim 41 , wherein said quality measuring unit measures a receiving quality of at least one radio channel transmitted from the base station.  
   
   
       43 . The mobile station according to  claim 41 , wherein said quality measuring unit uses, as a radio channel for measurement of the receiving quality at said mobile station, one selected from an annunciation information channel, an individual channel, a multicast channel, and a combination of these, among said at least one radio channel transmitted from the base station.  
   
   
       44 . The mobile station according to  claim 41 , wherein said receiving quality is one selected from at least one of the following: 
 a received power;      C/(I+N)  (Eq. 1)    C: carrier power    I: interference power    N: noise power;      S/(I+N)  (Eq. 2)    S: signal power    I: interference power    N: noise power;      C/N  (Eq. 3)    C: carrier power    N: noise power;      S/N  (Eq. 4)    S: signal power    N: noise power;    an error rate;    a likelihood obtained in decoding of error correction code;    a transmission power value of the base station; and    an increase amount or an attenuation amount of the transmission power of the base station.    
   
   
       45 . The mobile station according to  claim 41 , wherein when a repeat request for retransmission of a received signal is needed, said notifying unit notifies said base station of said repeat request, together with said receiving quality of the radio signal measured.  
   
   
       46 . The mobile station according to  claim 41 , wherein on an occasion of notifying said base station of an acknowledgement of arrival of a received signal, said notifying unit notifies the base station of the receiving quality of said at least one radio channel measured.  
   
   
       47 . The mobile station according to  claim 41 , wherein said notifying unit notifies the base station of a number of at least one radio channel and a receiving quality of the radio channel, or of only a channel number of a receiving quality within a predetermined range, as the receiving quality of said at least one radio channel measured.  
   
   
       48 . The mobile station according to  claim 41 , wherein said notifying unit notifies said base station of a number of at least one radio channel satisfying a required receiving quality, including a radio channel with a maximum receiving quality at said mobile station, together with the receiving quality achieved.  
   
   
       49 . The mobile station according to  claim 41 , wherein radio channels used between said mobile station and said base station are at least one of subcarrier channels, orthogonal subcarrier channels, frequency channels, and frequency channels in different frequency bands.