Method and system for wireless communication channel estimation
AssigneeTelefonaktiebolaget L M Ericsson (publ)
InventorsEliana Yepez, Jinliang Huang, Edward Mah, Fredrik Huss
Life of this patent
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Abstract
A method and system for selecting an algorithm for channel estimation in a wireless communication system are disclosed. According a parameter indicative of an accuracy of a channel estimation algorithm is determined. A selection between a first channel estimation algorithm and a second channel estimation algorithm is made based on the determined parameter.
Claims14
A method of selecting an algorithm for channel estimation in a communication system, the method comprising:
- calculating a parameter indicative of an accuracy of a channel estimation algorithm, the parameter being calculated based on a summation of square differences of channel estimates at different times normalized by an estimated received power, the estimate of the received power being determined after channel estimation, the summation being over a number of transmit antennas, a number of receive antennas, and a number of subcarriers;
- and
- selecting between a first channel estimation algorithm and a second channel estimation algorithm based on the parameter.
A method of selecting an algorithm for channel estimation in a communication system, the method comprising:
- calculating a parameter indicative of an amount of a temporal variation in a channel estimate, the parameter being calculated based on a summation of square differences of channel estimates at different times;
- selecting between a first channel estimation algorithm and a second channel estimation algorithm based on the parameter;
- and
- the selecting including:
- comparing the parameter to a threshold, the threshold being based at least in part on a probability distribution of the parameter, the threshold being further based at least in part on a signal to noise ratio of a signal transmitted through the channel, the signal to noise ratio being measured after channel estimation;
- and
- determining when the parameter indicates one of a low temporal variation and a high temporal variation.
A method of selecting an algorithm for channel estimation in a communication system, the method comprising:
- calculating a parameter indicative of an accuracy of a channel estimation algorithm, the parameter being calculated based on a summation of square differences of channel estimates at different times, the parameter being indicative of an amount of a temporal variation in a channel estimate;
- and
- selecting between a first channel estimation algorithm and a second channel estimation algorithm based on the parameter, the selecting including:
- comparing the parameter to a threshold, the threshold being approximated by a polynomial function based on a probability distribution of the parameter;
- and
- determining when the parameter indicates one of a low temporal variation and a high temporal variation, the threshold being approximated by
- Θ
-
- (
- p
- )
- =
- Θ
- ~
-
- (
- p
- )
- S
-
-
- N
- ~
-
- R
- lin
- where SÑRlin is an estimated received signal to noise ratio in linear scale after channel estimation, and
- {tilde over (Θ)}(p)≈−2.3339p4+8.0448p3−10.8173p2+6.8343p−0.7244
- where pε[50,100]% is a percentage point.
A method of selecting an algorithm for channel estimation in a communication system, the method comprising:
- calculating a parameter indicative of an accuracy of a channel estimation algorithm, the parameter being calculated based on a summation of square differences of channel estimates at different times normalized by an estimated received power, the estimate of the received power being determined after channel estimation;
- selecting between a first channel estimation algorithm and a second channel estimation algorithm based on the parameter, the parameter being given by:
- θ
- n
- =
- θ
- P
- ~
- r
- and where {tilde over (P)}r is an estimated received power after channel estimation and the summation is given by one of
- θ
- =
- 1
- 2
-
- N
- T
-
- N
- R
-
- F
-
- ∑
- j
- =
- 1
- N
- T
-
-
- ∑
- i
- =
- 1
- N
- R
-
-
- ∑
- f
- =
- 1
- F
-
-
- (
- Re
-
- (
- H
- ~
- f
- ij
-
- (
- n
- 1
- )
- )
- -
- Re
-
- (
- H
- ~
- f
- ij
-
- (
- n
- 2
- )
- )
- )
- 2
- +
- (
- Im
-
- (
- H
- ~
- f
- ij
-
- (
- n
- 1
- )
- )
- -
- Im
-
- (
- H
- ~
- f
- ij
-
- (
- n
- 2
- )
- )
- )
- 2
- and a multiple thereof, and where NT is a quantity of transmit antennas, NR is a quantity of receive antennas, F is a number of subcarriers, and {tilde over (H)}fij(nk) is an estimate of the channel frequency response between antennas i and j at a time nk of the fth subcarrier.
A method of selecting an algorithm for channel estimation in a communication system, the method comprising:
- calculating a parameter indicative of an accuracy of a channel estimation algorithm, the parameter being calculated based on a summation of square differences of channel estimates at different times, the parameter being further based on a difference between an approximate mean square error of an averaging algorithm and an approximate mean square error of a linear interpolation algorithm, the difference being approximately given by
- MSEΔ=MSEavg−MSElinear≈8P(1−J0(7ω0))−8.28σz2
- where P is a transmit signal power, Jo is a zero order Bessel function of the first kind, ωo is ω0=2πfDTs fD a Doppler frequency, Ts is the OFDM symbol interval and σz2 is an estimation of a noise variance of a channel, and where J0(7ω0) is obtained from θ=2P(1−J0(7ω0))+2σz2;
- and
- selecting between a first channel estimation algorithm and a second channel estimation algorithm based on the parameter.
A non-transitory computer readable medium containing computer readable instruction that, when executed by a processor, cause the processor to perform functions that include:
- calculating a parameter indicative of an accuracy of a channel estimation algorithm for estimating a channel in a communication system, the parameter being calculated based on a summation of square differences of channel estimates at different times, the parameter being based at least in part on a temporal variation of the channel, the parameter being further based at least in part on a measure of an estimated received signal to noise ratio after channel estimation;
- and
- selecting a channel estimation algorithm to estimate a channel based on the parameter.
Dependencies are inferred from the claim text.