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US 2003/0152021 A1Published application
Post-fft scaling to reduce multiple effects
AssigneeAtheros Communications, Inc.
InventorsYi-Hsiu Wang, Jeffrey M. Gilbert
Life of this patent
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Abstract
A method of scaling at a receiver representations of training signals received from a transmitter. The method includes producing a frequency domain representation of at least one long training symbol received at the receiver and a frequency domain representation of a data symbol, and scaling the frequency domain representation of the at least one long symbol based on a largest coefficient in the frequency domain representation to produce a scaled frequency domain representation of the at least one long symbol.
Claims72
A receiver including an equalization circuit that has a scaling circuit to scale representations of signals received from a transmitter, the receiver comprising:
- a frequency domain transform unit that is to produce a frequency domain representation of at least one training symbol received at the receiver and a frequency domain representation of a data symbol;
- and
- a scaling circuit that is to scale the frequency domain representation of the at least one training symbol based upon a largest coefficient in the frequency domain representation of the at least one training symbol to produced a scaled frequency domain representation of the at least one training symbol.
A receiver including an equalization circuit that has a scaling circuit for scaling representations of signals received from a transmitter, the receiver comprising:
- a frequency domain transform unit that is to produce a frequency domain representation of at least one training symbol received at the receiver and a frequency domain representation of a data symbol;
- a scaling circuit that is to scale the frequency domain representation of the at least one training symbol based on a largest coefficient in the frequency domain representation of the at least one training symbol to produce a scaled frequency domain representation of the at least one training symbol;
- a divider circuit that is to divide the scaled frequency domain representation of the at least one training symbol by a frequency domain representation of the at least one training symbol that is based on a time domain representation of a training symbol that is substantially not influenced by channel effects to produce a channel estimate;
- an inversion circuit that is to produce an inverted channel estimate by inverting the channel estimate;
- and
- a multiplier that is to multiply the frequency domain representation of the data symbol by the inverted channel estimate.
3 more elements
A receiver including an equalization circuit that has a scaling circuit for scaling representations of signals received from a transmitter, the receiver comprising:
- a frequency domain transform unit that is to produce a frequency domain representation of at least one training symbol received at the receiver and a frequency domain representation of a data symbol;
- a scaling circuit that is to scale the frequency domain representation of the at least one training symbol based on a largest coefficient in the frequency domain representation of the at least one training symbol to produce a scaled frequency domain representation of the at least one training symbol;
- a divider circuit that is to divide the scaled adjusted frequency domain representation of the at least one training symbol by a frequency domain representation of the at least one training symbol that is based on a time domain representation of a training symbol that is substantially not influenced by channel effects;
- an inversion circuit that is to produce an inverted channel estimate by inverting the channel estimate;
- a multiplier that is to multiply the frequency domain representation of the data symbol by the inverted channel estimate to produce channel adjusted frequency domain representation of the data symbol;
- and
- a second scaling circuit that is to scale the channel adjusted frequency domain representation of the data symbol based on a second largest coefficient in the channel adjusted frequency domain representation of the data symbol.
4 more elements
A method of scaling at a receiver representations of training signals received from a transmitter, the method comprising:
- producing a frequency domain representation of at least one training symbol received at the receiver and a frequency domain representation of a data symbol;
- scaling the frequency domain representation of the at least one training symbol based on a largest coefficient in the frequency domain representation of the at least one training symbol is less than a threshold to produce a scaled frequency domain representation of the at least one training symbol;
- and
- producing a channel estimate by dividing the scaled frequency domain representation of the at least one training symbol by a frequency domain representation of the at least one training symbol that is based on a time domain representation of a training symbol that is substantially not influenced by channel effects.
1 more element
A method of scaling at a receiver representations of training signals received from a transmitter, the method comprising:
- producing a frequency domain representation of at least one training symbol received at the receiver and a frequency domain representation of a data symbol;
- scaling the frequency domain representation of the at least one training symbol based on a largest coefficient in the frequency domain representation of the at least one training symbol to produce a scaled frequency domain representation of the at least one training symbol;
- producing a channel estimate by dividing the scaled frequency domain representation of the at least one training symbol by a frequency domain representation of the at least one training symbol that is based on a time domain representation of a training symbol that is substantially not influenced by channel effects;
- producing an inverted channel estimate by inverting the channel estimate;
- and
- multiplying the frequency domain representation of the data symbol by the inverted channel estimate.
3 more elements
A method of scaling at a receiver representations of training signals received from a transmitter, the method comprising:
- producing a frequency domain representation of at least one training symbol received at the receiver and a frequency domain representation of a data symbol;
- scaling the frequency domain representation of the at least one training symbol based on a largest coefficient in the frequency domain representation of the at least one training symbol to produce a scaled frequency domain representation of the at least one training symbol;
- producing a channel estimate by dividing the scaled frequency domain representation of the at least one training symbol by a frequency domain representation of the at least one training symbol that is based on a time domain representation of a training symbol that is substantially not influenced by channel effects;
- producing an inverted channel estimate by inverting the channel estimate;
- multiplying the frequency domain representation of the data symbol by the inverted channel estimate to produce channel adjusted frequency domain representation of the data symbol;
- and
- scaling the channel adjusted frequency domain representation of the data symbol when a second largest coefficient in the channel adjusted frequency domain representation of the data symbol is less than a threshold.
4 more elements
A receiver including an equalization circuit that has a scaling circuit for scaling representations of signals received from a transmitter, the receiver comprising:
- a frequency domain transform unit that is to produce a frequency domain representation of at least one training symbol received at the receiver and a frequency domain representation of a data symbol;
- a scaling circuit that is to scale the frequency domain representation of the at least one training symbol based on a largest coefficient in the frequency domain representation of the at least one training symbol to produce a scaled frequency domain representation of the at least one training symbol;
- an offset compensation circuit that is to convolve the scaled frequency domain representation of the at least one training symbol with a frequency domain representation of a periodic signal to produce an offset adjusted scaled frequency domain representation of the at least one training symbol;
- and
- a divider circuit that is to divide the offset adjusted scaled frequency domain representation of the at least one training symbol by a frequency domain representation of the training symbol that is based on a time domain representation of a training symbol that is substantially not influenced by channel effects.
2 more elements
A receiver including an equalization circuit that has a scaling circuit for scaling representations of signals received from a transmitter, the receiver comprising:
- a frequency domain transform unit that is to produce a frequency domain representation of at least one training symbol received at the receiver and a frequency domain representation of a data symbol;
- a scaling circuit that is to scale the frequency domain representation of the at least one training symbol based upon a largest coefficient in the frequency domain representation of the at least one training symbol to produce a scaled frequency domain representation of the at least one training symbol;
- a frequency offset compensation circuit that is to convolve the scaled frequency domain representation of the at least one training symbol with a frequency domain representation of a periodic signal to produce an offset adjusted frequency domain representation of the at least one training symbol;
- a divider circuit that is to divide the offset adjusted frequency domain representation of the at least one training symbol by a frequency domain representation of the at least one training symbol that is based on a time domain representation of a training symbol that is substantially not influenced by channel effects to produce a channel estimate;
- an inversion circuit that is to produce an inverted channel estimate by inverting the channel estimate;
- and
- a multiplier that is to multiply the frequency domain representation of the data symbol by the inverted channel estimate.
4 more elements
A receiver including an equalization circuit that has a scaling circuit for scaling representations of signals received from a transmitter, the receiver comprising:
- a frequency domain transform unit that is to produce a frequency domain representation of at least one training symbol received at the receiver and a frequency domain representation of a data symbol;
- a scaling circuit that is to scale the frequency domain representation of the at least one training symbol based on a largest coefficient in the frequency domain representation of the at least one training symbol to produce a scaled frequency domain representation of the at least one training symbol;
- a frequency offset compensation circuit that is to convolve the scaled frequency domain representation of the at least one training symbol by a frequency domain representation of a periodic signal to produce an offset adjusted scaled frequency domain representation of the at least one training symbol;
- a divider circuit that is to divide the offset adjusted scaled frequency domain representation of the at least one training symbol by a frequency domain representation of the at least one training symbol that is based on a time domain representation of a training symbol that is substantially not influenced by channel effects to produce a channel estimate;
- an inversion circuit that is to produce an inverted channel estimate by inverting the channel estimate;
- a multiplier that is to multiply the frequency domain representation of the data symbol by the inverted channel estimate to produce channel adjusted frequency domain representation of the data symbol;
- and
- a second scaling circuit that is to scale the channel adjusted frequency domain representation of the data symbol when a second largest coefficient in the channel adjusted frequency domain representation of the data symbol is less than a threshold.
5 more elements
A method of scaling at a receiver representations of training signals received from a transmitter, the method comprising:
- producing a frequency domain representation of at least one training symbol received at the receiver and a frequency domain representation of a data symbol;
- scaling the frequency domain representation of the at least one training symbol when a largest coefficient in the frequency domain representation of the at least one training symbol is less than a threshold to produce a scaled frequency domain representation of the at least one training symbol;
- producing an offset adjusted scaled frequency domain representation of the at least one training symbol by convolving the scaled frequency domain representation of the at least one training symbol by a frequency domain representation of a periodic signal;
- and
- producing a channel estimate by dividing the offset adjusted scaled frequency domain representation of the at least one training symbol by a frequency domain representation of the at least one training symbol that is based on a time domain representation of a training symbol that is substantially not influenced by channel effects.
2 more elements
The method of claim 78, further comprising multiplying the frequency domain representation of the data symbol by the inverted channel estimate to produce a channel adjusted frequency domain frequency representation of the data symbol.
A method of scaling at a receiver representations of training signals received from a transmitter, the method comprising:
- producing a frequency domain representation of at least one training symbol received at the receiver and a frequency domain representation of a data symbol;
- scaling the frequency domain representation of the at least one training symbol based on a largest coefficient in the frequency domain representation of the at least one training symbol is less than a threshold to produce a scaled frequency domain representation of the at least one training symbol;
- producing an offset adjusted scaled frequency domain representation of the at least one training symbol by convolving the scaled frequency domain representation of the at least one training symbol by a frequency domain representation of a periodic signal;
- producing a channel estimate by dividing the offset adjusted scaled frequency domain representation of the at least one training symbol by a frequency domain representation of the at least one training symbol that is based on a time domain representation of a training symbol that is substantially not influenced by channel effects;
- producing an inverted channel estimate by inverting the channel estimate;
- and
- multiplying the frequency domain representation of the data symbol by the inverted channel estimate.
4 more elements
A method of scaling at a receiver representations of training signals received from a transmitter, the method comprising:
- producing a frequency domain representation of at least one training symbol received at the receiver and a frequency domain representation of a data symbol;
- scaling the frequency domain representation of the at least one training symbol based on a largest coefficient in the frequency domain representation of the at least one training symbol to produce a scaled frequency domain representation of the at least one training symbol;
- producing an offset adjusted frequency domain representation of the at least one training symbol by convolving the frequency domain representation of the at least one training symbol by a frequency domain representation of a periodic signal;
- and
- producing a channel estimate by dividing the offset adjusted scaled frequency domain representation of the at least one training symbol by a frequency domain representation of the at least one training symbol that is based on a time domain representation of a training symbol that is substantially not influenced by channel effects;
- producing an inverted channel estimate by inverting the channel estimate;
- multiplying the frequency domain representation of the data symbol by the inverted channel estimate to produce channel adjusted frequency domain representation of the data symbol;
- and
- scaling the channel adjusted frequency domain representation of the data symbol when a second largest coefficient in the channel adjusted frequency domain representation of the data symbol is less than a threshold.
6 more elements
Dependencies are inferred from the claim text.