Radio transmission device and radio transmission method

Abstract

It is possible to improve the CQI reception performance even when a delay is caused in a propagation path, a transmission timing error is caused, or a residual interference is generated between cyclic shift amounts of different ZC sequences. For the second symbol and the sixth symbol of the ACK/NACK signal which are multiplexed by RS of CQI, (+, +) or (−, −) is applied to a partial sequence of the Walsh sequence. For RS of CQI transmitted from a mobile station, + is added as an RS phase of the second symbol and − is added as an RS phase of the sixth symbol. A base station (100) receives multiplexed signals of ACK/NACK signals and CQI signals transmitted from a plurality of mobile stations. An RS synthesis unit (119) performs synthesis by aligning the RS phase of CQI.

1 . A radio transmitting apparatus comprising:
 an acknowledgement/negative acknowledgement signal transmission processing section that spreads an acknowledgement/negative acknowledgement signal using an orthogonal sequence;   a reference signal phase adding section that adds a phase according to part of the orthogonal sequence, to a reference signal of a channel quality indicator multiplexed with the acknowledgement/negative acknowledgement spread using the orthogonal sequence; and   a transmitting section that transmits a channel quality indicator signal including the reference signal to which the phase is added.   
     
     
         2 . The radio transmitting apparatus according to  claim 1 , wherein:
 the reference signal phase adding section adds to the reference signal the phase according to part of the orthogonal sequence of higher priority in the orthogonal sequence to which priority of use is assigned.   
     
     
         3 . The radio transmitting apparatus according to  claim 1 , wherein:
 the reference signal phase adding section adds the phase to the reference signal according to a number of radio transmitting apparatuses that use a pair of orthogonal sequences in which part of codes for spreading the acknowledgement/negative acknowledgement signal multiplexed with the reference signal is an in-phase, and a number of radio transmitting apparatuses that use a pair of orthogonal sequences in which part of codes for spreading the acknowledgement/negative acknowledgement signal multiplexed with reference signal is a reverse phase.   
     
     
         4 . The radio transmitting apparatus according to  claim 1 , wherein:
 the reference signal phase adding section adds to the reference signal the phase according to part of codes used to perform second spreading of an acknowledgement/negative acknowledgement signal which is multiplexed with the reference signal and which is subjected to first spreading using a Zadoff-Chu sequence which is adjacent to a Zadoff-Chu sequence used to spread a channel quality indicator and which is associated with a smaller cyclic shift amount than a cyclic shift amount of the Zadoff-Chu sequence used to spread the channel quality indicator   
     
     
         5 . The radio transmitting apparatus according to  claim 1 , wherein:
 orthogonal sequences are used to perform second spreading of the acknowledgement/negative acknowledgement signal that is subjected to first spreading using a Zadoff-Chu sequence associated with a cyclic shift amount which is consecutive to a cyclic shift amount of the Zadoff-Chu sequence used to spread the channel quality indicator; and   the reference signal phase adding section adds the phase to the reference signal according to a number of radio transmitting apparatuses using the orthogonal sequence in which part of codes used to perform second spreading of the acknowledgement/negative acknowledgement signal multiplexed with the reference signal is an in-phase and a number of radio transmitting apparatuses that use the orthogonal sequence in which part of codes used to perform second spreading of the acknowledgement/negative acknowledgement signal multiplexed with the reference signal is a reverse phase.   
     
     
         6 . The radio transmitting apparatus according to  claim 1 , wherein:
 in case where a signal superimposing the acknowledgement/negative acknowledgement signal on the channel quality indicator has a phase orthogonal to part of an orthogonal sequence used by an acknowledgement signal that applies the greatest interference to the signal, the reference signal phase adding section makes the acknowledgement/negative acknowledgement signal to be superimposed on the channel quality indicator a negative acknowledgement signal.   
     
     
         7 . The radio transmitting apparatus according to  claim 1 , wherein:
 in case where a signal superimposing the acknowledgement/negative acknowledgement signal on the channel quality indicator has a phase orthogonal to part of an orthogonal sequence used by an acknowledgement signal that applies the greatest interference to the signal, the reference signal phase adding section makes the acknowledgement/negative acknowledgement signal to be superimposed on the channel quality indicator an acknowledgement signal.   
     
     
         8 . The radio transmitting apparatus according to  claim 6 , wherein:
 the reference signal phase adding section adds to the reference signal of the superimposed signal a phase according to part of the orthogonal sequence of higher priority in the orthogonal sequence to which priority of use is assigned.   
     
     
         9 . A radio receiving apparatus comprising:
 a receiving section that received an acknowledgement/negative acknowledgement signal spread by using an orthogonal sequence, and a channel quality indicator signal including a plurality of reference signals to which a phase is added according to part of the orthogonal sequence, each of the reference signals are multiplexed with the acknowledgement/negative acknowledgement;   an acknowledgement/negative acknowledgement signal reception processing section that despread the acknowledgement/negative acknowledgement signal using the orthogonal sequence; and   a RS combining section that coordinates and combines the phases of the plurality of reference signals.   
     
     
         10 . A radio transmitting method comprising:
 an acknowledgement/negative acknowledgement signal transmission processing step of spreading an acknowledgement/negative acknowledgement signal using an orthogonal sequence;   a reference signal phase adding step of adding a phase according to part of the orthogonal sequence, to a reference signal of a channel quality indicator multiplexed with the acknowledgement/negative acknowledgement signal spread using the orthogonal sequence; and   a transmitting step of transmitting a channel quality indicator signal including the reference signal to which the phase is added.   
     
     
         11 . A radio receiving method comprising:
 a receiving step of receiving an acknowledgement/negative acknowledgement signal spread by using an orthogonal sequence, and a channel quality indicator signal including a plurality of reference signals to which a phase is added according to part of the orthogonal sequence, each of the reference signals are multiplexed with the acknowledgement/negative acknowledgement;   an acknowledgement/negative acknowledgement signal reception processing step of despreading the acknowledgement/negative acknowledgement signal using the orthogonal sequence; and   a RS combining step of coordinating and combining the phases of the plurality of reference signals.