Wireless transmitter and reference signal transmission method

• US 10,263,744 B2
• Filed: 01/28/2010
• Issued: 04/16/2019
• Est. Priority Date: 01/29/2009
• Status: Active Grant

• Current Assignee: Sun Patent Trust
• Original Assignee: Sun Patent Trust
• Inventors: Iwai, Takashi, Futagi, Sadaki, Takata, Tomohumi, Imamura, Daichi, Ogawa, Yoshihiko
• Primary Examiner(s): Pan, Yuwen
• Assistant Examiner(s): Tran, Paul P
• Application Number:
  US13/146,611
• Publication Number:
  US 20110287797A1
• Time in Patent Office: 3,365 Days
• Field of Search: 455283, 455296, 455307, 4554221, 455442, 455506, 455509, 455450, 455500, 455513, 370203, 370204, 370208, 370209, 370210, 370329, 370335, 370338, 370342, 370344, 370468, 370491, 375260, 375344
• 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. A transmission apparatus comprising:

a receiver, which, in operation, receives, from a base station, allocation information indicating one or two sets of consecutive frequency resources allocated in each of one or more uplink component carriers, which include a first component carrier and a second component carrier when more than one uplink component carrier are configured, the first component carrier and the second component carrier having different frequency, and the two sets of consecutive frequency resources being spaced apart from each other along a frequency axis;

circuitry, which, in operation, based on the received allocation information, performs one of;

a first operation of generating plural uplink reference signal sequences including a first sequence and a second sequence, mapping the generated first sequence in said one or two sets of consecutive frequency resources allocated in the first component carrier, mapping the generated second sequence in said one or two sets of consecutive frequency resources allocated in the second component carrier, and controlling transmission of the mapped first sequence and the mapped second sequence; and

a second operation of generating one uplink reference signal sequence, mapping the generated one uplink reference signal sequence in said two sets of consecutive frequency resources allocated in said one uplink component carrier by dividing the generated one uplink reference signal sequence into two subsequences correspondingly to said two sets of consecutive frequency resources, respectively, and controlling transmission of the mapped one uplink reference signal sequence,

wherein the first operation and the second operation are switched based on a number of said one or more uplink component carriers.

2. The transmission apparatus according to claim 1, wherein the generated one or plural uplink reference signal sequence(s) are cyclic shift sequences.

3. The transmission apparatus according to claim 1, wherein when a number of said one or more uplink component carriers is two, a number of the generated plural uplink reference signal sequences is two.

4. The transmission apparatus according to claim 1, wherein a sequence number of the generated first sequence is different from a sequence number of the generated second sequence.

5. The transmission apparatus according to claim 1, wherein

a first length of the generated first sequence corresponds to a bandwidth of the one or two sets of consecutive frequency resources allocated in the first component carrier, and a second length of the generated second sequence corresponds to a bandwidth of the one or two sets of consecutive frequency resources allocated in the second component carrier.

6. The transmission apparatus according to claim 1, wherein a length of the generated first sequence mapped in one set of consecutive frequency resources allocated in the first component carrier is different from a length of the generated second sequence mapped in two sets of consecutive frequency resources allocated in the second component carrier.

7. A transmission method performed by a transmission apparatus, the transmission method comprising:

receiving, from a base station, allocation information indicating one or two sets of consecutive frequency resources allocated in each of one or more uplink component carriers, which include a first component carrier and a second component carrier when more than one uplink component carrier are configured, the first component carrier and the second component carrier having different frequency, and the two sets of consecutive frequency resources being spaced apart from each other along a frequency axis;

performing, based on the received allocation information, one of;

a first operation of generating plural uplink reference signal sequences including a first sequence and a second sequence, mapping the generated first sequence in said one or two sets of consecutive frequency resources allocated in the first component carrier, mapping the generated second sequence in said one or two sets of consecutive frequency resources allocated in the second component carrier, and transmitting the mapped first sequence and the mapped second sequence; and

a second operation of generating one uplink reference signal sequence, mapping the generated one uplink reference signal sequence in said two sets of consecutive frequency resources allocated in said one uplink component carrier by dividing the generated one uplink reference signal sequence into two subsequences correspondingly to said two sets of consecutive frequency resources, respectively, and transmitting the mapped one uplink reference signal sequence,

wherein the first operation and the second operation are switched based on a number of said one or more uplink component carriers.

8. The transmission method according to claim 7, wherein the generated one or plural uplink reference(s) signal sequences are cyclic shift sequences.

9. The transmission method according to claim 7, wherein when a number of said one or more uplink component carriers is two, a number of the generated plural uplink reference signal sequences is two.

10. The transmission method according to claim 7, wherein a sequence number of the generated first sequence is different from a sequence number of the generated second sequence.

11. The transmission method according to claim 7, wherein

a first length of the generated first sequence corresponds to a bandwidth of the one or two sets of consecutive frequency resources allocated in the first component carrier, and a second length of the generated second sequence corresponds to a bandwidth of the one or two sets of consecutive frequency resources allocated in the second component carrier.

12. The transmission method according to claim 7, wherein a length of the generated first sequence mapped in one set of consecutive frequency resources allocated in the first component carrier is different from a length of the generated second sequence mapped in two sets of consecutive frequency resources allocated in the second component carrier.