1. A digital communications receiver for receiving a vestigial sideband (VSB) signal representing a sequence of encoded symbols each representative of a plurality of data bits, the receiver comprising:
an input configured to receive a VSB signal from a communications channel;
an amplification and filtration device coupled to the input and configured to adjust a magnitude of, and to filter, the VSB signal to produce a scaled and filtered VSB signal; and
a virtual sub-carrier estimator coupled to the amplification and filtration device and configured to process the scaled and filtered VSB signal to estimate virtual sub-carriers such that the virtual sub-carriers are conjugate symmetric.
2. The receiver of claim 1 wherein the virtual sub-carrier estimator is configured to alter the scaled and filtered VSB signal such that a time-domain matrix indicative of characteristics of the channel is in circulant form, to convert the circulant matrix to frequency domain, and to determine a first set of symbol values using the converted matrix of channel characteristics and a second set of data points indicated by the scaled and filtered VSB signal, where the first set includes fewer symbol values than data points included in the second set.
3. The receiver of claim 2 wherein the virtual sub-carrier estimator is configured to produce a third quantity of symbol values by using the first quantity of symbol values for a first portion of the third quantity of symbol values, and using conjugates of some of the first quantity of symbol values to determine a second portion of the third quantity of symbol values.
4. The receiver of claim 3 wherein the first and second portions of the third quantity of symbol values are disposed on opposite sides of half of a symbol rate for the received signal.
5. The receiver of claim 2 wherein the second quantity of data points includes in-band data and out-of-band data.
6. The receiver of claim 2 wherein the second quantity of data points includes in-band data, and the virtual sub-carrier estimator is configured to set values for out of band data points to zero.
7. The receiver of claim 1 wherein the virtual sub-carrier estimator is a frequency domain turbo equalizer.
8. An integrated circuit chip for receiving and processing a vestigial sideband (VSB) signal representing a sequence of encoded symbols each representative of a plurality of data bits, the chip comprising:
an input configured to receive a VSB signal from a communications channel;
front-end processing circuitry coupled to the input and configured to alter characteristics of the VSB signal to produce a modified signal having a desired format; and
virtual sub-carrier estimator circuitry coupled to the front-end processing circuitry and configured to process the modified signal to estimate virtual sub-carriers such that the virtual sub-carriers are conjugate symmetric.
9. The chip of claim 8 wherein the virtual sub-carrier estimator circuitry is configured to alter the modified signal such that a time-domain matrix indicative of characteristics of the channel is in circulant form, to convert the circulant matrix to frequency domain, and to determine a first set of symbol values using the converted matrix of channel characteristics and a second set of data points indicated by the modified signal, where the first set includes fewer symbol values than data points included in the second set.
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 process of forming a stent comprising the steps of:
providing a sacrificial template which defines a stent pattern;
applying at least one layer of material over at least a portion of the stent pattern of the sacrificial template; and
eliminating said sacrificial template.
2. The process of claim 1 wherein the stent pattern is defined by a plurality of interconnected indentations defined by the sacrificial template.
3. The process of claim 2 further comprising the step of:
positioning at least one fiber into at least one of the indentations.
4. The process of claim 3 wherein the at least one fiber is positioned into the at least one of the indentations after application of the at least one material.
5. The process of claim 3 wherein the at least one fiber is positioned into the at least one of the indentations before application of the at least one material.
6. The process of claim 1 wherein the at least one layer of material comprises a polymeric composition and said material fills the plurality of indentations.
7. The process of claim 2 wherein the at least one fiber is braided, woven, knitted, roving, or wound.
8. The process of claim 2 wherein the at least one fiber comprises a plurality of fibers, the plurality of fibers being arranged randomly, in the form of a braided, inter-woven, or wound.
9. The process of claim 1 wherein the at least one layer of material comprises a plurality of distinct layers of material, each layer being applied over the sacrificial template separately from one another.
10. The process of claim 11 wherein said sacrificial template comprises a water dispersible or water soluble polymer.
11. The process of claim 10 wherein said polymer is selected from the group consisting of polyvinyl alcohol, polyvinyl acetate or mixtures thereof.
12. The process of claim 11 wherein the sacrificial template is eliminated by the step of flushing said sacrificial structure with water at a temperature of about 25\xb0 C. to about 110\xb0 C.
13. The process of claim 1 wherein the at least one layer of material comprises at least one thermoplastic polymer.
14. The process of claim 13 wherein said thermoplastic polymer is selected from the group consisting of polyesters, polyamides, polyolefins, polyurethanes, polyethers, polyimides, any copolymers thereof, styrenic block copolymers and mixtures thereof.
15. The process of claim 13 wherein said thermoplastic polymer is selected from the group consisting of poly(ester block ester), poly(ester block ether), poly(ether block amide), polyalkylene terephthalate or mixture thereof.
16. The process of claim 2 further comprising the step of:
positioning at least enhancement device into at least one of the indentations, the at least one enhancement device being at least one device selected from the group consisting of: sensors, detectable markers, marker bands, conductive coils, and any combination thereof.
17. The process of claim 2 wherein following the elimination of the sacrificial template an expandable stent is provided from the at least one layer of material, the stent comprising a stent body constructed of a plurality of interconnected stent members which correspond to the shape and arrangement of the plurality of interconnected indentations.
18. The process of claim 17 further comprising the step of removing at least one of the a plurality of interconnected stent members from the stent body.
19. The process of claim 17 wherein at least a portion of the stent body has a tapering diameter when the stent is placed in an expanded state.
20. The process of claim 17 wherein the body defines a flow path therethrough, adjacent interconnected stent members define a side branch opening through the stent body, the side branch opening being in fluid communication with the flow path.
21. The process of claim 1 wherein the stent pattern is defined by a plurality of channels defined by the sacrificial template.
22. A template for forming a stent, the template comprising a sacrificial material.
23. The template of claim 22 defining a negative stent pattern, the negative stent patter comprising a plurality of interconnected indentations.