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US 8,797,994 B2Granted
Frequency offset estimation method, communication apparatus, wireless communication system, and program
AssigneeNEC Corporation
InventorKengo Oketani
Life of this patent
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Abstract
A frequency offset estimation unit estimates a frequency offset by combining information on a maximum window having a maximum peak power obtained from a received PRACH (Physical Random Access Channel) signal and a sign of a phase of a correlation value between channel estimation values obtained from a received PUSCH (Physical Uplink Shared Channel) signal.
Claims10
A frequency offset estimation method, comprising:
- performing channel estimation from a received PUSCH (Physical Uplink Shared Channel) signal;
- estimating a frequency offset by combining:
- information on a maximum window having a maximum peak power, obtained from a received PRACH (Physical Random Access Channel) signal, and
- a sign of a phase of a correlation value between channel estimation values obtained from the received PUSCH signal;
- and
- estimating the frequency offset from the phase of the correlation value between the channel estimation values, based on:
- a correspondence relationship between each frequency segment of a first frequency segment group obtained by dividing an estimable frequency offset range and the maximum window;
- and
- a relationship between each frequency segment of a second frequency segment group obtained by dividing the estimable frequency offset range and the sign of the correlation value between the channel estimation values.
6 more elements
A frequency offset estimation method, comprising:
- performing channel estimation from a received PUSCH (Physical Uplink Shared Channel) signal;
- estimating a frequency offset by combining:
- information on a maximum window having a maximum peak power, obtained from a received PRACH (Physical Random Access Channel) signal, and
- a sign of a phase of a correlation value between channel estimation values obtained from the received PUSCH signal:
- detecting respective maximum path powers of a plurality of mutually different windows from the received PRACH signal, using the plurality of mutually different windows;
- selecting one of the windows corresponding to the maximum power from among the detected maximum path powers;
- and
- estimating the frequency offset, using information on the phase of the correlation value between the channel estimation values and the sign of the phase and the information on the maximum window,
- wherein the windows includes a center window, a left window, and a right window, the method comprising:
- with argR [radian] being an argument of a complex correlation value R, wherein R is a complex number, between the channel estimation values obtained from the received PUSCH signal being indicated and a duration between reference symbols in a former-half slot, and Ts[s] being a latter-half slot of a PUSCH subframe,
- determining a frequency offset Δf according to the following expression,
- in case the argR is greater than or equal to 0 and less than π, and the maximum window is the center window or the right window:
- Δ
-
-
- f
- =
- arg
-
-
- R
-
- [
- radian
- ]
- 2
-
- π
- ×
- 1
- T
- S
-
- [
- s
- ]
- in case the argR is greater than or equal to 0 and less than π, and the maximum window is the left window:
- Δ
-
-
- f
- =
- (
- arg
-
-
- R
-
- [
- radian
- ]
- 2
-
- π
- -
- 1
- )
- ×
- 1
- T
- S
-
- [
- s
- ]
- in case the argR is greater than or equal to −π and less than 0, and the maximum window is the center window or the left window:
- Δ
-
-
- f
- =
- arg
-
-
- R
-
- [
- radian
- ]
- 2
-
- π
- ×
- 1
- T
- S
-
- [
- s
- ]
- and,
- in case the argR is greater than or equal to −π and less than 0, and the maximum window is the right window:
- Δ
-
-
- f
- =
- (
- arg
-
-
- R
-
- [
- radian
- ]
- 2
-
- π
- +
- 1
- )
- ×
- 1
- T
- S
-
- [
- s
- ]
- the estimable frequency offset range being set to a range greater than or equal to −1/Ts [Hz] and less than +1/Ts [Hz].
118 more elements
A non-transitory computer-readable storage medium having a frequency offset estimation program stored therein for causing a computer to execute the processing comprising:
- performing channel estimation from a received PUSCH (Physical Uplink Shared Channel) signal;
- and
- estimating a frequency offset by combining:
- information on a maximum window having a maximum peak power, obtained from a received PRACH (Physical Random Access Channel) signal;
- and
- a sign of a phase of a correlation value between channel estimation values obtained from a received PUSCH signal,
- wherein the frequency offset estimation processing estimates the frequency offset from the phase of the correlation value between the channel estimation values, based on:
- a correspondence relationship between each frequency segment of a first frequency segment group obtained by dividing an estimable frequency offset range and the maximum window;
- and
- a relationship between each frequency segment of a second frequency segment group obtained by dividing the estimable frequency offset range and the sign of the correlation value between the channel estimation values.
7 more elements
A non-transitory computer-readable storage medium having a frequency offset estimation program stored therein for causing a computer to execute the processing comprising:
- performing channel estimation from a received PUSCH (Physical Uplink Shared Channel) signal;
- estimating a frequency offset by combining:
- information on a maximum window having a maximum peak power, obtained from a received PRACH (Physical Random Access Channel) signal;
- and
- a sign of a phase of a correlation value between channel estimation values obtained from a received PUSCH signal,
- detecting respective maximum path powers of a plurality of mutually different windows from the received PRACH signal, using the plurality of mutually different windows;
- selecting a window corresponding to the maximum power from among the detected maximum path powers;
- and
- estimating the frequency offset, using information on the phase of the correlation value between the channel estimation values and the sign of the phase and the information on the maximum window from the maximum path window selection unit,
- wherein the windows includes a center window, a left window, and a right window, the program stored in the storage medium causing the computer to execute the processing further comprising:
- with argR [radian] being an argument of a complex correlation value R, wherein R is a complex number, between the channel estimation values obtained from the received PUSCH signal, and Ts[s] being a duration between reference symbols in a former-half slot and a latter-half slot of a PUSCH subframe,
- determining a frequency offset Δf according to the following expression,
- in case the argR is greater than or equal to 0 and less than π, and the maximum window is the center window or the right window:
- Δ
-
-
- f
- =
- arg
-
-
- R
-
- [
- radian
- ]
- 2
-
- π
- ×
- 1
- T
- S
-
- [
- s
- ]
- in case the argR is greater than or equal to 0 and less than π, and the maximum window is the left window:
- Δ
-
-
- f
- =
- (
- arg
-
-
- R
-
- [
- radian
- ]
- 2
-
- π
- -
- 1
- )
- ×
- 1
- T
- S
-
- [
- s
- ]
- in case the argR is greater than or equal to −π and less than 0, and the maximum window is the center window or the left window:
- Δ
-
-
- f
- =
- arg
-
-
- R
-
- [
- radian
- ]
- 2
-
- π
- ×
- 1
- T
- S
-
- [
- s
- ]
- and,
- in case the argR is greater than or equal to −π and less than 0, and the maximum window is the right window:
- Δ
-
-
- f
- =
- (
- arg
-
-
- R
-
- [
- radian
- ]
- 2
-
- π
- +
- 1
- )
- ×
- 1
- T
- S
-
- [
- s
- ]
- the estimable frequency offset range being set to a range greater than or equal to −1/Ts [Hz] and less than +1/Ts [Hz].
119 more elements
Dependencies are inferred from the claim text.