1. In a communications receiver having a decision feedback equalizer filter, the communications receiver responsive to a received signal that is over-sampled with respect to a symbol rate, an apparatus comprising:
a forward filter that receives the over-sampled signal and is adaptive based on a first feedback signal;
a first adder that sums an output of the forward filter with a second feedback signal to produce a new over-sampled signal;
a de-interleaver, clocked at an over-sampling rate associated with the over-sampled signal, that receives the new over-sampled signal;
a slicer, coupled to the de-interleaver, for quantizing on-baud samples from the new over-sampled signal;
an estimator, coupled to receive off-baud samples from the de-interleaver and receive the guantized samples from the slicer, for calculating approximate mid-level voltages for off-baud samples from the new over-sampled signal; an error term calculator, coupled to receive the on-baud samples and the quantized samples from the new over-sampled signal, for calculating the first feedback signal;
an interleaver, clocked at the over-sampling rate, and coupled to the de-interleaver, wherein the interleaver receives the quantized samples and receives off-baud samples from the new over-sampled signal; and
a feedback filter coupled to receive an output signal from the interleaver and to produce the second feedback signal for the first adder, wherein the feedback filter is adaptive based on the first feedback signal from the error term calculator.
2. In a communications receiver having a decision feedback equalizer filter, the communications receiver responsive to a received signal that is over-sampled with respect to a symbol rate, an apparatus comprising:
a forward filter that receives the over-sampled signal and is adaptive based on a first feedback signal;
a first adder that sums an output of the forward filter with a second feedback signal to produce a new over-sampled signal;
a de-interleaver, clocked at an over-sampling rate associated with the over- sampled signal, that receives the new over-sampled signal;
a slicer, coupled to the de-interleaver, for quantizing on-baud samples from the new over-sampled signal;
an error term calculator, coupled to receive the on-baud samples and the quantized samples from the new over-sampled signal, for calculating the first feedback signal;
an interleaver, clocked at the over-sampling rate, and coupled to the de-interleaver, wherein the interleaver receives the quantized samples and receives off-baud samples from the new over-sampled signal; and
a feedback filter coupled to receive an output signal from the interleaver and to produce the second feedback signal for the first adder, wherein the feedback filter is adaptive based on the first feedback signal from the error term calculator;
a first multiplier, coupled to the de-interleaver, for multiplying the on-baud samples from the new over-sampled signal with a first error term from the error term calculator;
a second multiplier, coupled to the slicer, for multiplying the quantized samples from the new over-sampled signal with a second error term from the error term calculator;
a third multiplier, coupled to the de-interleaver, for multiplying the on-baud samples from the new over-sampled signal with a third error term from the error term calculator;
a fourth multiplier, coupled to an output of the second multiplier, for multiplying the quantized samples from the new over-sampled signal with a fourth error term from the error term calculator; and
a second adder for summing outputs from the third and fourth multipliers to produce an input signal to the interleaver.
3. In a communications receiver having a decision feedback equalizer filter, the communications receiver responsive to a received signal that is over-sampled with respect to a symbol rate, an apparatus comprising:
a forward filter that receives the over-sampled signal and is adaptive based on a first feedback signal;
a first adder that sums an output of the forward filter with a second feedback signal to produce a new over-sampled signal;
a de-interleaver, clocked at an over-sampling rate associated with the over-sampled signal, that receives the new over-sampled signal;
a slicer, coupled to the de-interleaver, for quantizing on-baud samples from the new over-sampled signal;
an error term calculator, coupled to receive the on-baud samples and the quantized samples from the new over-sampled signal, for calculating the first feedback signal;
an interleaver, clocked at the over-sampling rate, and coupled to the de-interleaver, wherein the interleaver receives the quantized samples and receives off-baud samples from the new over-sampled signal; and
a feedback filter coupled to receive an output signal from the interleaver and to produce the second feedback signal for the first adder, wherein the feedback filter is adaptive based on the first feedback signal from the error term calculator;
a first multiplier, coupled to the de-interleaver, for multiplying the on-baud samples from the new over-sampled signal with a first error term from the error term calculator;
a second multiplier, coupled to the slicer, for multiplying the quantized samples from the new over-sampled signal with a second error term from the error term calculator; and
a second adder for summing outputs from the first and second multipliers to produce an input signal to the interleaver.
4. In a communications receiver responsive to a received signal that is over-sampled with respect to a symbol rate of the received signal, an apparatus for at least combating inter-symbol interference (ISI) in the received signal, the apparatus comprising:
a decision feedback equalizer, wherein the decision feedback equalizer includes:
an error term calculator that determines error values based on the over-sampled signal; a slicer for quantizing samples in a feedback signal that are on-baud;
an estimator configured to estimate quantized samples from the received signal when the received signal includes symbols that are off-baud with respect to an ideal symbol rate for the received signal;
a fractionally-spaced forward, transversal filter that processes the over-sampled signal, wherein the fractionally-spaced forward, transversal filter is adaptive based on the error values produced by the error term calculator; and
a fractionally-spaced feedback filter that processes the over-sampled signal, wherein the fractionally-spaced feedback filter is coupled to the fractionally-spaced forward, transversal filter, and is adaptive based on the error values produced by the error term calculator.
5. The apparatus of claim 4, wherein the apparatus employs samples in the feedback signal that are off-baud under a linear, infinite impulse response (IIR) filter.
6. The apparatus of claim 4 wherein the fractionally-spaced forward, transversal filter and fractionally-spaced feedback filter are adaptive only at baud instances.
7. The apparatus of claim 4, further comprising an initializing section configured to generate initial feedback filter coefficients for at least the fractionally-spaced feedback filter.
8. The apparatus of claim 4, further comprising:
a tuner configured to receive a digital television signal;
a front end processor configured to process the digital television signal; and
a decoder for decoding the processed digital television signal.
9. In a communications receiver that receives a signal, a method for at least combating inter-symbol interference (ISI) in the received signal, the method comprising:
receiving an input signal that is over-sampled with respect to a symbol rate of the received signal; and
decision feedback equalizing the over-sampled input signal, wherein the decision feedback equalizing includes:
forward, transversal filtering the over-sampled input signal based on first equalizer coefficients, wherein first equalizer coefficients adjacent in time are less than a symbol interval apart with respect to the received signal;
feedback filtering the over-sampled input signal with second equalizer coefficients, wherein second equalizer coefficients adjacent in time are less than a symbol interval apart with respect to the received signal, calculating error values based on the over-sampled input signal;
adapting the forward, transversal filtering and the feedback filtering based at least in part on the calculated error values; and
wherein the method further comprises quantizing samples in a feedback signal that are on-baud with respect to an ideal symbol rate for the received signal, and wherein the feedback filtering includes infinite impulse response (IIR) filtering employing samples off-baud with respect to the ideal symbol rate for the received signal.
10. The method of claim 9 wherein the adapting is performed only at the symbol rate.
11. The method of claim 9 further comprising estimating quantized samples from the received signal when the received signal includes symbols that are off-rate with respect to an ideal symbol rate for the received signal.
12. The method of claim 9 further comprising initializing at least the feedback filtering.
13. The method of claim 9 further comprising:
tuning to a desired frequency to receive a digital television signal;
front end processing the received digital television signal; and
decoding the processed digital television signal.
14. a communications receiver that receives a signal, a method for at least combating inter-symbol interference (ISI) in the received signal, the method comprising:
receiving an input signal that is over-sampled with respect to a symbol rate of the received signal; and
decision feedback equalizing the over-sampled input signal, wherein the decision feedback equalizing includes:
forward, transversal filtering the over-sampled input signal based on first equalizer coefficients, wherein first equalizer coefficients adjacent in
time are less than a symbol interval apart with respect to the received signal;
feedback filtering the over-sampled input signal with second equalizer coefficients, wherein second equalizer coefficients adjacent in time are less than a symbol interval apart with respect to the received signal,
calculating error values based on the over-sampled input signal;
adapting the forward, transversal filtering and the feedback filtering based at least in part on the calculated error values; wherein the method further comprises quantizing samples in a feedback signal that are on-baud with respect to an ideal symbol rate for the received signal; and
wherein the method further comprises estimating quantized samples from the received signal when the received signal includes symbols that are off-baud with respect to an ideal symbol baud for the received signal.
15. The method of claim 14, wherein the feedback filtering includes infinite impulse response (IIR) filtering employing samples off-baud with respect to the ideal symbol rate for the received signal.
16. The method of claim 14 wherein the adapting is performed only at the symbol rate.
17. The method of claim 14, further comprising initializing at least the feedback filtering.
18. The method of claim 14, further comprising:
tuning to a desired frequency to receive a digital television signal;
front end processing the received digital television signal; and
decoding the processed digital television signal.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A display device, comprising:
a front side with a screen mounted thereon;
a rear side opposite to the front side;
a stand mounted on the rear side, the stand comprising a first supporting piece pivotably connected with the rear side and a second supporting piece inclinedly connected to the first supporting piece; and
a circuit board mounted on the first supporting piece.
2. The display device of claim 1, wherein the first supporting piece defines a plurality of securing holes, the circuit board defines a plurality of through holes, the plurality of through holes are aligned to the plurality of securing holes, and a plurality of fasteners are mounted in the plurality of through holes and the plurality of securing holes to mount the circuit board on the first supporting piece.
3. The display device of claim 1, wherein a cover is mounted on the first supporting piece to shield the circuit board.
4. The display device of claim 3, wherein the cover comprises a shield plate and a pair of side walls inclinedly connected to opposite edges of the shield plate, the shield plate and the pair of side walls together surrounds a receiving space, the pair of side walls is located on the first supporting piece, and the circuit board is received in the receiving space.
5. The display device of claim 4, wherein the receiving space comprises an opening, the circuit board comprises a plurality of connectors, a plurality of cables extends through the opening to connect to the plurality of connectors.
6. The display device of claim 1, wherein a mounting portion is protruded on the rear side, the mounting portion defines a pivot hole, and a shaft is mounted on the first supporting piece and pivotably received in the pivot hole.
7. The display device of claim 6, wherein the first supporting piece defines a first cutout, the mounting portion is received in the first cutout, the first supporting piece comprises a pair of ear pieces, each of the pair of ear pieces defines a fixing hole, and opposite ends of the shaft are inserted in the fixing holes of the pair of ear pieces to fix the shaft on the stand.
8. The display device of claim 7, wherein the first supporting piece comprises two first clips located on opposite sides of the first cutout, a cover comprises two second clips, and the two first clips engage with the second clips.
9. The display device of claim 1, wherein the second supporting piece is mounted with a skid-proof sleeve, and a bottom edge of the display device is mounted with a skid-proof cushion.
10. The display device of claim 1, wherein the screen is a touch screen.
11. A display device, comprising:
a front side comprising a screen;
a rear side opposite to the front side, a stand mounted on the rear side, the stand comprising a first supporting piece and a second supporting piece inclinedly connected to the first supporting piece, the first supporting piece pivotably connected with the rear side;
wherein the stand is configured to support the screen between a first position and a second position; in the first position, the second supporting piece is parallel placed on a work surface, and the rear side is configured to rotate with respect to the first supporting piece; in the second position, the first supporting piece is located on the rear side, an end of the second support piece and an bottom edge of the display device is located on the work surface to support the display device.
12. The display device of claim 11, wherein the end of second supporting piece is mounted with a skid-proof sleeve, and the bottom edge of the display device is mounted with a skid-proof cushion.
13. The display device of claim 11, wherein the screen is a touch screen.
14. The display device of claim 11, wherein a circuit board is mounted on the first supporting piece.
15. The display device of claim 14, wherein a cover is mounted on the first supporting piece to shield the circuit board.
16. The display device of claim 15, wherein the cover comprises a shield plate and a pair of side walls inclinedly connected to opposite edges of the shield plate, the shield plate and the pair of side walls together surrounds a receiving space, the pair of side walls is located on the first supporting piece, and the circuit board is received in the receiving space.
17. The display device of claim 16, wherein the receiving space comprises an opening, the circuit board comprises a plurality of connectors, a plurality of cables extends through the opening to connect to the plurality of connectors.
18. The display device of claim 11, wherein a mounting portion is protruded on the rear side, the mounting portion defines a pivot hole, and a shaft is mounted on the first supporting piece and pivotably mounted in the pivot hole.
19. The display device of claim 18, wherein the first supporting piece defines a first cutout, the mounting portion is received in the first cutout, the first supporting piece comprises a pair of ear pieces, each of the pair of ear pieces defines a fixing hole, and opposite ends of the shaft are inserted in the fixing holes of the pair of ear pieces to fix the shaft on the stand.
20. The display device of claim 19, wherein the first supporting piece comprises two first clips located on opposite sides of the first cutout, a cover comprises two second clips, and the two first clips engage with the second clips.