Author: claimsbot

1. A slotted expandable centraliser.
2. A centraliser as claimed in claim 1, having a body with a bore to accept a tubular, and being adapted to expand radially from a non-expanded configuration to an expanded configuration.
3. A centraliser as claimed in claim 2, wherein the slots are longitudinal in the non-expanded configuration and diamond-shaped in the expanded configuration.
4. A centraliser as claimed in claim 2, being adapted to receive an expandable tubular and adapted to deform radially with the expandable tubular upon expansion of the tubular.
5. A centraliser as claimed in claim 2, wherein the centraliser has at least one blade that projects radially outward of the body in the non-expanded configuration.
6. A centraliser as claimed in claim 5, wherein the at least one blade projects radially outward of the body in the expanded configuration.
7. A centraliser as claimed in claim 5, wherein the at least one blade is adapted to change configuration during expansion of the centraliser.
8. A centraliser as claimed in claim 5, wherein the at least one blade is adapted to retain its configuration during expansion of the centraliser.
9. A centraliser as claimed in claim 5, wherein the at least one blade has the same thickness as the body.
10. A centraliser as claimed in claim 1, having slotted portions circumferentially adjacent to non-slotted portions.
11. A centraliser as claimed in claim 10, the centralizer having a body with a bore to accept a tubular, and being adapted to expand radially from a non-expanded configuration to an expanded configuration, and at least one blade that projects radially outward of the body in the non-expanded configuration, wherein the at least one blade is located in a non-slotted portion.
12. A centraliser as claimed in claim 1, wherein the slots are uniformly distributed over the centraliser.
13. A centraliser as claimed in claim 1 wherein the slots are arranged in longitudinally aligned rows with slots in adjacent rows being axially offset with respect to one another so that the ends of circumferentially adjacent slots overlap.
14. A centraliser as claimed in claim 1, wherein the slots are of uniform dimension.
15. A centraliser as claimed in claim 1, being adapted to deform plastically.
16. A centraliser as claimed in claim 1, being adapted to deform elastically.
17. A centraliser as claimed in claim 1, being a casing centraliser.
18. A centraliser assembly comprising a slotted expandable centraliser which has a body with a bore to accept a tubular, and is radially expandable from a non-expanded configuration to an expanded configuration; and an expandable tubular, located in the bore of the centraliser.
19. An assembly as claimed in claim 18, wherein the centraliser is a casing centraliser.
20. An assembly as claimed in claim 18, wherein the tubular comprises casing, liner or a screen.

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 digital signal equalizer comprising
a plurality of multiplexers, wherein number of multiplexers defines resolution of equalization, wherein the plurality of multiplexers are configured in groups, wherein number of groups is based on number of taps, wherein number of multiplexers associated with a particular group is based on equalization range for the group, and wherein the multiplexers in each group select a digital value associated with the cursor or a non-cursor tap associated with the group.
2. The equalizer of claim 1, wherein the multiplexers select the appropriate digital value based on equalization desired.
3. The equalizer of claim 2, wherein the multiplexers receive coefficients based on the desired equalization and the coefficients are used to select the appropriate digital value.
4. The equalizer of claim 1, wherein the digital value associated with the non-cursor tap is a complement of the tap digital signal.
5. The equalizer of claim 1, wherein the digital value associated with the non-cursor tap is selected as a complement of the tap digital signal or the tap digital signal, where the selection is platform dependent.
6. The equalizer of claim 1, wherein equalization can be turned off by selecting the digital value associated with the cursor for each multiplexer.
7. The equalizer of claim 1, where number of taps considered in equalization can be reduced by selecting the digital value associated with the cursor for each multiplexer in a tap group where the tap is to be excluded from equalization.
8. The equalizer of claim 1, further comprising a plurality of flip flops aligned with the plurality of multiplexers, wherein the multiplexers are to align all the selected digital values.
9. The equalizer of claim 8, further comprising a digital to analog converter (DAC) to convert the plurality of digital values into a single analog signal.
10. The equalizer of claim 1, wherein the plurality of multiplexers includes a first set associated with an odd half of a two way interleaved data stream and a second set associated with an even set, wherein the first and second set have same group configurations, and further comprising a 2-to-1 multiplexer to combine the digital values from the first set and the second set.
11. A digital signal equalizer comprising
an odd bit multiplexer based equalization including a first plurality of multiplexers arranged in a first plurality of groups, wherein each of the first plurality of groups is associated with a non-cursor tap and selects either an odd cursor or the non-cursor tap based on equalization parameters defined, wherein number of multiplexers in the first plurality of multiplexers defines resolution of equalization, wherein number of groups in the first plurality of groups is based on number of taps, and wherein number of multiplexers associated with a particular group is based on distance associated non-cursor tap is away from the odd cursor;
an even bit multiplexer based equalization including a second plurality of multiplexers arranged in a second plurality of groups, wherein each group of the second plurality of groups is associated with a non-cursor tap and selects either an even cursor or the non-cursor tap based on equalization parameters defined, wherein number of multiplexers in the second plurality is same as first plurality, and wherein number of groups in second plurality is same as first plurality; and
a 2-to-1 multiplexer to combine associated outputs from the odd bit multiplexer based equalization and the even bit multiplexer based equalization.
12. The equalizer of claim 11, wherein the odd bit multiplexer based equalization further includes a first plurality of flip flops equal in number to the number of multiplexers in the first plurality of multiplexers to clock an output of an associated multiplexer according to a first clock signal, and wherein the even bit multiplexer based equalization further includes a second plurality of flip flops equal in number to the number of multiplexers in the second plurality of multiplexers to clock an output of an associated multiplexer according to a second clock signal.
13. The equalizer of claim 12, wherein the odd bit multiplexer based equalization further includes a first plurality of inverters equal in number to the number of flip flops in the first plurality of flip flops to generate an inverted output, and wherein the even bit multiplexer based equalization further includes a second plurality of inverters equal in number to the number of flip flops in the second plurality of flip flops to generate an inverted output, wherein the 2-to-1 multiplexer is to combine associated outputs and inverted outputs from the odd bit multiplexer based equalization and the even bit multiplexer based equalization.
14. The equalizer of claim 11, further comprising a pre-driverdriver to convert output of the 2-to-1 multiplexer into an analog signal.
15. The equalizer of claim 11, wherein number or taps considered in equalization can be reduced by selecting the digital value associated with the cursor for each multiplexer in a tap group where the tap is to be excluded from equalization and equalization can be turned off by selecting the digital value associated with the cursor for all multiplexers.
16. A system comprising
a first processor having a transmitter to transmit data, wherein the transmitter includes a multiplexer based equalizer;
a second processor having a receiver to receive data; and
a data link between the first and the second processor.
17. The system of claim 16, wherein the multiplexer based equalizer includes a plurality of multiplexers, wherein number of multiplexers defines resolution of equalization, wherein the plurality of multiplexers are configured in groups, wherein number of groups is based on number of taps, wherein number of multiplexers associated with a particular group is based on equalization range for the group, and wherein the multiplexers in each group select a digital value associated with the cursor or a tap associated with the group.
18. The system of claim 17, wherein equalization can be turned off by selecting the digital value associated with the cursor for each multiplexer.
19. The system of claim 17, where number of taps considered in equalization can be reduced by selecting the digital value associated with the cursor for each multiplexer in the tap group.
20. The equalizer of claim 17, further comprising a plurality of flip flops aligned with the plurality of multiplexers, wherein the multiplexers are to align all the selected digital values.

1. A 3D device adapted to produce an image comprising an opacity estimate predictor adapted to predict opacity of at least one primitive using at least one first equation derived from at least one second equation used to compute opacity.
2. The 3D device of claim 1, wherein said first equation comprises MIN value={(A==0b00)|(B==0b00) & (SubCD)|(C==0b00)|(D==0b00) & (SubE)|(E==0b00)}|{SubCD & (C==0b11) & (D==0b11) & (SubE)|(E==0b00)|(A==0b00) & (B==0b00)}|{SubE & (E==0b11) & (SubCD)|(C==0b00) & (D==0b00)|(A==0b00) & (B==0b00)} and MAX value={(A==0b11) & (B==0b11) & (\u02dcSubCD)|(C==0b00)|(D==0b00) & (\u02dcSubE)|(E==0b00)}|{(A==0b11) & (B==0b11) & (\u02dcSubCD) & (C==0b11) & (D==0b11)}|{(A==0b11) & (B==0b11) & (\u02dcSubE) & (E==0 b11)}|{(\u02dcSubCD) & (C==0b11) & (D==0b11) & (\u02dcSubE)|(E==0b00)}|{(\u02dcSubCD) & (C==0b11) & (D==0b11) & (\u02dcSubE) & (E==0b11)}|{(\u02dcSubE) & (E==0b11) & (\u02dcSubCD)|(C==0b00)|(D=0b00)}.
3. The 3D device of claim 1, wherein said second equation comprises (A*B\xb1C*D\xb1E)<<S.
4. The 3D device of claim 3, wherein said first equation is based on at least axioms 1.0*1.0=1.0, 0.0*x=0.0, 1.0+x=1.0 when clamped, 0.0\u2212x=0.0 when clamped, x\u22121.0=0.0 when clamped, 0.0<<n=0.0 and 1.0<<n=1.0 when clamped.
5. The 3D device of claim 1 wherein the opacity estimate predictor is further adapted to reject said primitive if said predicted opacity is less than or equal to a minimum value, and further comprising a texture module adapted to compute opacity of at least one non-rejected primitive.
6. The 3D device of claim 5, wherein said texture module is further adapted to compute said opacity according to the at least one second equation.
7. The 3D device of claim 6, wherein said second equation comprises (A*B\xb1C*D\xb1E)<<S.
8. The 3D device of claim 7, wherein said second equation is based on said first equation.
9. The 3D device of claim 5, wherein said texture module is further adapted to blend non-rejected primitives.
10. The 3D device of claim 1, further comprising a register communicating with at least said predictor and adapted to store a primitive list.
11. The 3D device of claim 10, further comprising an X-loop and Y-loop communicating with at least said register and adapted to determine at least one relevant scan line.
12. The 3D device of claim 11, further comprising a Z-order device communicating with at least the X-loop and Y-loop and adapted to order the primitives.
13. A 3D core for producing an image using at least two primitives comprising:
an opacity estimate predictor adapted to predict opacity of the primitives using at least one first formula and reject at least one of the primitives if said predicted opacity is equal to a minimum value;
a register adapted to store a list of said non-rejected primitives; and
a texture device adapted to compute the opacity of the non-rejected primitives using at least one second formula.
14. The 3D core of claim 13 wherein said first formula is derived using said second formula.
15. The 3D core of claim 13 further adapted to parse said list of non-rejected primitives.
16. The 3D core of claim 15 further adapted to reject any non-rejected primitives that are behind any non-rejected primitives having a predicted maximum opacity value.
17. The 3D core of claim 13, further comprising an X-loop and Y-loop communicating with at least said register and adapted to determine at least one relevant scan line.
18. The 3D core of claim 17, further comprising a Z-order device communicating with at least the X-loop and Y-loop and adapted to order the primitives.
19. A method for producing an image, the method comprising:
predicting opacity of primitives represented by data used to produce the image, using at least one first equation;
rejecting select data based at least in part on said predicted opacity, forming a group of non-rejected data; and
computing opacity for said group using at least one second equation; and
blending said group, forming the image.
20. The method of claim 19, wherein forming said group comprises rejecting at least one of said data having a minimum predicted opacity value.
21. The method of claim 19, wherein forming said group comprises rejecting at least one of said data behind data having a maximum predicted opacity value.
22. The method of claim 19, further comprising ordering said group from a back to a front of the image.
23. The method of claim 19, further comprising generating a data list.
24. The method of claim 19, further comprising identifying data for at least one display line of the image.
25. The method of claim 19, wherein said second equation is based on said first equation.
26. The method of claim 19, wherein said first equation comprises a plurality of equations.
27. The method of claim 19, wherein said second equation comprises a plurality of equations.
28. A method of computing opacity of a plurality of primitives used to produce an image, the method comprising:
predicting an opacity value of the primitives using at least one first equation;
rejecting at least one of the primitives based at least in part on said predicted opacity value;
generating a primitive list of first non-rejected primitives;
identifying at least one of the primitives from said list for at least one display line of the image;
ordering said first non-rejected primitives;
rejecting at least one of said first non-rejected primitives based at least partially on said predicted opacity value forming second non-rejected primitives;
computing opacity for said second non-rejected primitives using at least one second equation; and
blending all said second non-rejected primitives, producing the image.
29. The 3D core of claim 28 wherein said first formula is derived using said second formula.

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 method of switching between transmission modes in an IEEE802.11n wireless communication system, comprising steps of:
determining, by a receiver, a decision metric as a function of post-detection constellation-coding SNR, said determining including:
estimating communication channel information based on long preamble;
computing a squared min-distance of constellation for different MCS (modulation coding scheme) with the same transmission rates; and
selecting between transmission modes based on the decision metric.
2. The method of claim 1, wherein selecting between transmission modes further includes selecting between spatial multiplexing, delay diversity and space-time coding transmission modes based on the decision metric.
3. The method of claim 2 further including comparing MCS of different transmission modes using the decision metric.
4. The method of claim 3 wherein selecting between transmission modes further includes selecting between transmission modes based on the decision metric to achieve the best system performance.
5. The method of claim 1, wherein determining a decision metric further includes determining a decision metric as a function of a constellation distance and coding rate.
6. The method of claim 5 wherein determining a decision metric further includes:
computing a post-detection SNR (\u03c1MIMO) for different transmission modes;
computing a coding loss of higher coding rate (\u03c1coding); and
computing a decision metric D for each transmission mode, such that each transmission mode has a corresponding decision metric.
7. The method of claim 6 wherein selecting the transmission modes further includes switching between the transmission modes based on the decision metric of each transmission mode.
8. The method of claim 6 wherein selecting the transmission modes further includes selecting the transmission mode with the largest decision metric.
9. The method of claim 8 wherein the communication system comprises a transmitter and a receiver, the method further comprising feeding back the selection information to the transmitter for switching between transmission modes accordingly.
10. The method of claim 6 wherein computing a decision metric D for each transmission mode further includes for each transmission mode computing:
D=\u03c1MIMOd2min-constellation\u2212\u03c1coding,
where (d2min-constellation) is the squared min-distance of constellation for different MCS with the same transmission rates.
11. The method of claim 10, wherein eigen-value computation for transmission mode selection is not performed.
12. The method of claim 10, wherein the communication system comprises a MIMO system.
13. A controller for switching between transmission modes in an IEEE802.11n wireless communication system, comprising:
a decision metric calculator configured for determining a decision metric as a function of post-detection constellation-coding SNR by:
estimating communication channel information based on long preamble;
computing a squared min-distance of constellation for different MCS (modulation coding scheme) with the same transmission rates; and

a selector that selects between transmission modes based on the decision metric.
14. The controller of claim 13, wherein the selector selects between transmission modes further by selecting between spatial multiplexing, delay diversity and space-time coding transmission modes based on the decision metric.
15. The controller of claim 14 further including means for comparing MCS of different transmission modes using the decision metric.
16. The controller of claim 15 wherein the selector selects between transmission modes further by selecting between transmission modes based on the decision metric to achieve the best system performance.
17. The controller of claim 16, wherein the decision metric calculator determines the decision metric further by determining a decision metric as a function of post detection SNR, a constellation distance and coding rate.
18. The controller of claim 17 wherein the decision metric calculator determines the decision metric further by:
computing a post-detection SNR (\u03c1MIMO) for different transmission modes;
computing a coding loss of higher coding rate (\u03c1coding); and
computing a decision metric D for each transmission mode, such that each transmission mode has a corresponding decision metric.
19. The controller of claim 18 wherein the selector selects the transmission modes further by switching between the transmission modes based on the decision metric of each transmission mode.
20. The controller of claim 18 wherein the selector selects the transmission modes further by selecting the transmission mode with the largest decision metric.
21. The controller of claim 20 wherein the communication system comprises a transmitter and a receiver, such that the controller further feeds back the selection information to the transmitter for switching between transmission modes accordingly.
22. The controller of claim 18 wherein decision metric calculator computes the decision metric D for each transmission mode further by, for each transmission mode, computing:
D=\u03c1MIMO+d2min-constellation\u2212\u03c1coding,
where (d2min-constellation) is the squared min-distance of constellation for different MCS with the same transmission rates.
23. The controller of claim 22, wherein eigen-value computation for transmission mode selection is not performed.
24. The controller of claim 22, wherein the communication system comprises a MIMO system.
25. The controller of claim 18, wherein post-detection SNR (\u03c1MIMO) for direct mapping mode is determined as min(1diag{R\u2020R\u2020H}), where R\u2020 is the MIMO equalizer coefficients computed using MMSE (Minimum Mean Squared Error) criterion or ZF (Zero Forcing) criterion.
26. The controller of claim 18, wherein post-detection SNR (\u03c1MIMO) for spatial spreading mode with number of spatial streams NSS=1 is determined as \u2225Hq\u2225F where \u2225H\u2225F is the Frobenius norm of the H matrix, defined as \u03a3j,k|hj,k|2,and q is the spatial spreading antenna map vector.
27. The controller of claim 18, wherein post-detection SNR (\u03c1MIMO) for spatial spreading mode with number of spatial streams Nss>1 is determined as min(1diag{R\u2020R\u2020H}) where R\u2020 is the MIMO equalizer coefficients based on the equivalent channel coefficient HQ, using the MMSE (Minimum Mean Squared Error) criterion or the ZF criterion, and Q is the spatial spreading matrix.
28. The controller of claim 27 wherein the \u03c1coding values are further optimized based on detailed implementation codes.
29. The controller of claim 18, wherein post-detection SNR (\u03c1MIMO) for STBC (Space-Time Block Coding) mode with number of spatial streams Nss=1 is determined as \u2225H\u2225F where \u2225H\u2225F is the Frobenius norm of the H matrix, defined as \u03a3j,k|hj,k|2.
30. The controller of claim 18, wherein post-detection SNR (\u03c1MIMO) for STBC (Space-Time Block Coding) mode with number of spatial streams Nss=2 is determined as min (\u2225H1\u2225F, \u2225H2\u03bcF) where H1 is first of two rows of channel matrix H, corresponding to the channel of the first data stream, and H2 are the third and fourth rows of the channel matrix H, corresponding to the second data stream.
31. The controller of claim 18, wherein post-detection SNR (\u03c1MIMO) for basic beamforming mode with power loading is determined as \u03c1MIMO=min(1diag{R\u2020R\u2020H}+diag(P1,P2, . . . ,PNss)), where R\u2020 is the MIMO equalizer coefficients based on the equivalent channel coefficient HQ, using the MMSE (Minimum Mean Squared Error) criterion or the ZF (Zero Forcing) criterion, Q is the eigen-steering matrix.
32. The controller of claim 18, wherein coding loss of higher coding rate (\u03c1coding) is determined as:
\u03c1coding (dB)
Rate 12 codes
0
Rate 23 codes
2
Rate 34 codes
3
Rate 56 codes
\u20094.
33. The controller of claim 18, wherein a squared mm-distance of constellation (d2min-constellation) for different MCS with the same transmission rates is determined as:
d2min-constellation
d2min-constellation (dB)
BPSK
4
6.02
QPSK
(2\u221a{square root over (2)})2
3.01
16QAM
(2\u221a{square root over (10)})2
\u22123.98
64QAM
(2\u221a{square root over (42)})2
\u221210.2.
34. A method of switching between transmission modes in an IEEE802.11n wireless communication system, comprising steps of:
Determining, by a receiver, a decision metric as a function of post-detection constellation-coding SNR including:
determining a decision metric as a function of a constellation distance and coding rate;
estimating communication channel information based on long preamble;
computing a post-detection SNR (PMIMO) for different transmission modes;
computing a coding loss of higher coding rate (P coding);
computing a squared min-distance of constellation (d^2 min_constellation) for different MCS (modulation coding scheme) with the same transmission rates; and
computing a decision metric D for each transmission mode, such that each transmission mode has a corresponding decision metric; and

selecting between transmission modes based on the decision metric.
35. A controller for switching between transmission modes in an IEEE802.11n wireless communication system, comprising:
a decision metric calculator configured for determining a decision metric as a function of post-detection constellation-coding SNR, a constellation distance and coding rate, the decision metric calculator further configured for:
estimating communication channel information based on long preamble;
computing a post-detection SNR (\u03c1MIMO) for different transmission modes;
computing a coding loss of higher coding rate (\u03c1coding);
computing a squared min-distance of constellation (d2min-constellation) for different MCS (modulation coding scheme) with the same transmission rates; and
computing a decision metric D for each transmission mode, such that each transmission mode has a corresponding decision metric; and

a selector that selects between transmission modes based on the decision metric.