Wireless base station apparatus, wireless terminal apparatus, frequency resource allocation method, and method of forming transmission signal
A wireless base station apparatus and wireless terminal apparatus with a configuration which can prevent reductions in the accuracy of channel estimation when non-contiguous band transmission and SRS transmission are employed in an uplink line. In the base station apparatus ( 100 ), an allocation setting unit ( 106 ), which sets the reception band of an SRS at an SRS extraction unit ( 103 ) and sets the units of frequency allocation (RBG) at a CQI estimation unit ( 104 ) and allocation unit ( 105 ), matches the frequency position at the end of the SRS reception band to the frequency position at the end of any of the units of frequency allocation and sets the reception bandwidth of the reference signal to a natural number multiple of the bandwidth of the unit of frequency allocation. In the terminal apparatus ( 200 ), a band information setting unit ( 204 ), which sets the transmission band and units of frequency allocation (RBG), matches the frequency position at the end of the transmission band to the frequency position at the end of any of the units of frequency allocation and sets the transmission bandwidth of the SRS to a natural number multiple of the bandwidth of the unit of frequency allocation.
1. A communication apparatus, comprising:
a receiver which, in operation, receives a downlink signal including a sounding reference signal (SRS) that is mapped to a SRS transmission band, the SRS transmission band being provided at a portion of a system band that includes a plurality of resource blocks (RBs), the plurality of resource blocks (RBs) being divided into a plurality of resource block groups (RBGs), and a frequency position of an edge of one of the plurality of RGBs being aligned with a frequency position of an edge of the SRS transmission band; and
an estimator which, in operation, estimates a channel quality indicator (CQI) using the SRS, a number of RBs included in the SRS transmission band being a multiple of a number of RBs that form one RBG.
2. The communication apparatus according to claim 1 wherein the estimator estimates the CQI for each of the plurality of RBGs.
3. The communication apparatus according to claim 1 , comprising a setting section which, in operation, sets a bandwidth of the SRS transmission band, a position of the SRS transmission band in the system band, and a frequency hopping pattern of the SRS transmission.
4. The communication apparatus according to claim 1 wherein the number of RBs that form one RBG is different depending on a bandwidth of the system band.
5. The communication apparatus according to claim 1 wherein a minimum number of RBs included in the SRS transmission band is 4.
6. The communication apparatus according to claim 1 wherein the number of RBs included in the SRS transmission band is a multiple of 4.
7. A communication method, comprising:
receiving a downlink signal including a sounding reference signal (SRS) that is mapped to a SRS transmission band, the SRS transmission band being provided at a portion of a system band that includes a plurality of resource blocks (RBs), the plurality of resource blocks (RBs) being divided into a plurality of resource block groups (RBGs), and a frequency position of an edge of one of the plurality of RGBs being aligned with a frequency position of an edge of the SRS transmission band; and
estimating a channel quality indicator (CQI) using the SRS, a number of RBs included in the SRS transmission band being a multiple of a number of RBs that form one RBG.
8. The communication method according to claim 7 wherein the estimation of the CQI is performed for each of the plurality of RBGs.
9. The communication method according to claim 7 , comprising setting a bandwidth of the SRS transmission band, a position of the SRS transmission band in the system band, and a frequency hopping pattern of the SRS transmission.
10. The communication method according to claim 7 wherein the number of RBs that form one RBG is different depending on a bandwidth of the system band.
11. The communication method according to claim 7 wherein a minimum number of RBs included in the SRS transmission band is 4.
12. The communication method according to claim 7 wherein the number of RBs included in the SRS transmission band is a multiple of 4.