WIRELESS TRANSMITTER AND REFERENCE SIGNAL TRANSMISSION METHOD

• US 20110287797A1
• Filed: 01/28/2010
• Published: 11/24/2011
• Est. Priority Date: 01/29/2009
• Status: Active Grant

• Current Assignee: Sun Patent Trust
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Iwai, Takashi, Futagi, Sadaki, Takata, Tomohumi, Imamura, Daichi, Ogawa, Yoshihiko
• Granted Patent: US 10,263,744 B2
• Time in Patent Office: Days
• US Class Current: 455/509
• CPC Class Codes: H04L 25/022 of frequency response
• CPC Class Codes: H04L 25/0226 sounding signals per se
• CPC Class Codes: H04L 25/03159 operating in the frequency domain H04L25/03165, H04L25/03178 take precedence
• CPC Class Codes: H04L 27/2613 Structure of the reference signals
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver

Abstract

Disclosed are a wireless transmitter and a reference signal transmission method that improve channel estimation accuracy. In a terminal (100), which transmits a reference signal using n (n is a non-negative integer 2 or greater) band blocks (which correspond to clusters here), which are disposed with spaces therebetween in a frequency direction, a reference signal controller (106) switches the reference signal formation method of a reference signal generator (107) between a first formation method and a second formation method based on the number (n) of band blocks. In addition, a threshold value setting unit (105) adjusts a switching threshold value based on the frequency spacing between band blocks. Thus, the reference signal formation method can be selected with good accuracy and, as a result, channel estimation accuracy is further improved.

Claims

1-6. -6. (canceled)

7. A radio transmission apparatus that transmits a reference signal using n (n is a natural number of 2 or greater) bandwidth blocks that are positioned at intervals from each other in a direction of frequency, the apparatus comprising:

a formation section that forms the reference signal based on one of a first formation method, in which n subsequences are formed as the reference signal by dividing one code sequence into a length to match each bandwidth block, and a second formation method, in which n code sequences are formed as the reference signal by adjusting lengths of n code sequences to match each bandwidth block; and

a switch section that switches reference signal formation methods in the formation section between the first formation method and the second formation method based on a switch threshold value and the number of the bandwidth blocks n.

8. The radio transmission apparatus according to claim 7, wherein the switch section switches the reference signal formation methods in the formation section based on a total bandwidth of n bandwidth blocks in addition to the switch threshold value and the number of the bandwidth blocks n.

9. The radio transmission apparatus according to claim 7, further comprising an adjusting section that adjusts the switch threshold value based on a frequency interval between the bandwidth blocks.

10. The radio transmission apparatus according to claim 7, wherein the switch section forms the reference signal using the first formation method when the number of the bandwidth blocks n is equal to or smaller than the switch threshold value, and forms the reference signal using the second formation method when the number of the bandwidth blocks n is greater than the switch threshold value.

11. The radio transmission apparatus according to claim 10, wherein the bandwidth block is a component carrier that is equivalent to a predetermined system bandwidth and is formed with a plurality of clusters.

12. A reference signal transmission method of transmitting a reference signal using n (n is a natural number of 2 or greater) bandwidth blocks that are positioned at intervals from each other in a direction of frequency, the method comprising:

forming the reference signal based on one of a first formation method, in which n subsequences are formed as the reference signal by dividing one code sequence into a length to match each bandwidth block, and a second formation method, in which n code sequences are formed as the reference signal by adjusting lengths of n code sequences to match each bandwidth block; and

switching reference signal formation methods between the first formation method and the second formation method based on a switch threshold value and the number of the bandwidth blocks n.

13. The reference signal transmission method according to claim 12, wherein reference signal formation methods in forming the reference signal are switched based on a total bandwidth of n bandwidth blocks in addition to the switch threshold value and the number of the bandwidth blocks n.

14. The reference signal transmission method according to claim 12, wherein the switch threshold value is adjusted based on a frequency interval between the bandwidth blocks.

15. The reference signal transmission method according to claim 12, wherein, in forming the reference signal, the reference signal is formed using the first formation method when the number of the bandwidth blocks n is equal to or smaller than the switch threshold value, and the reference signal is formed using the second formation method when the number of the bandwidth blocks n is greater than the switch threshold value.

16. The reference signal transmission method according to claim 15, wherein the bandwidth block is a component carrier that is equivalent to a predetermined system bandwidth and is formed with a plurality of clusters.