1. A cue ball deflection path teaching aid, comprising;
a cue ball path grid including a main neutral line, a perpendicular transverse line, and two diagonal lines extending on opposite sides of said main neutral line, said main neutral line being aligned with said longitudinal axis of said cue stick and said transverse line crossing said main neutral line and creating a center intersection point, said diagonal lines extending from said center point 60 degrees above said transverse line.
2. The teaching aid as recited in claim 2, wherein said grid is printed on a transparent material thereby said cue stick to be visible under said grid.
3. A cue ball deflection path teaching aid, comprising;
a cue ball path grid including indicia defining a main neutral line, a transverse line perpendicular to said main neutral line and an intersecting point, said indicia further defining two forward extending diagonal lines aligned approximately 60 degrees from said transverse line, said diagonal lines converge and are aligned with said intersecting point between said main neutral line and said transverse line, and wherein said main neutral line corresponds with said longitudinal axis of said cue stick.
4. The teaching aid as recited in claim 3 wherein said main neutral line on said cue ball path grid is denoted by at least two dots.
5. The teaching aid as recited in claim 3 wherein said transverse line on said cue ball path grid is denoted by at least two dots or dashes.
6. The teaching aid as recited in claim 3 wherein each said diagonal lines on said cue ball path grid is denoted by at least two dots or dashes.
7. A method for teaching a user the deflection paths of a cue ball having a top spin, a backspin or having no spin, said method comprises the steps of:
a. selecting a cue ball path deflection aid including a grid comprising a main neutral line, a perpendicular transverse line, and two diagonal lines located on opposite sides of said main neutral line, said main neutral line and said transverse line forming a center intersection point and said diagonal lines extending forward from said center intersection point 30 degrees above said transverse line;
b. selecting a spin type for said ball shot;
for a top spin shot, aligning said cue stick over the cue ball path and observing the orientation of said diagonal lines on the side opposite the object ball in order to determine the deflection path of said cue ball,
for a back spin shot, aligning said cue stick over an object ball path, determining a length of a first line segment which extends perpendicular from said object ball path to said cue ball and extending the first line across said object ball path and determining a point along an extended first line segment which is twice the length of a first line segment, extending a line from said object ball to a point along the extended first line segment in order to determine the deflection path of said cue ball, and
for a no spin shot, aligning said cue stick over said object ball path, using said transverse line to determine the deflection path of said cue ball; and,
c. executing a shot as determined in step d and observing the deflection path of said cue ball.
8. A cue ball deflection path teaching aid, comprising;
b. a cue ball path grid including a visual indicia denoting a transverse line parallel to said transverse axis and perpendicular to said longitudinal axis of said cue stick and two diverging diagonal lines that begin at or visually extended forward from a visual or non visual intersection point formed between said longitudinal axis and said transverse axis, each said diagonal line extends forward on said curved surface on opposite sides of said longitudinal axis approximately 30 degrees.
9. The teaching aid as recited in claim 8 wherein said grid further includes a visual main neutral line aligned with said longitudinal axis of said cue stick.
10. The teaching aid as recited in claim 9 wherein said main neutral line is denoted by at least two dots.
11. The teaching aid as recited in claim 8 wherein each said diagonal lines on said cue ball path grid is denoted by at least two dots or dashes.
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 receiver apparatus in a multi-user communication system, the receiver apparatus comprising:
a multi-user detector for creating a soft decision value using a plurality of received signals and information output from a prior iteration of a decoding process;
a channel decoder for performing local iterative decoding on the soft decision value created by the multi-user detector, for updating the soft decision value, and for controlling local iterative decoding for the soft decision value according to a global iterative decoding; and
a global decoding controller for checking the soft decision value updated by the channel decoder, and for controlling whether or not to perform the global iterative decoding.
2. The receiver apparatus as claimed in claim 1, wherein the multi-user detector comprises:
an interference cancellation unit for detecting each user signal by applying a parallel interference cancellation scheme to the plurality of received signals; and
a bandpass unit for removing an interference component remaining in each user signal.
3. The receiver apparatus as claimed in claim 1, wherein the soft decision value corresponds to a log likelihood ratio.
4. The receiver apparatus as claimed in claim 1, wherein the global decoding controller comprises:
a threshold-value storage unit for storing a termination threshold value to determine a termination of global iterative decoding based on a simulation; and
a comparison unit for comparing a soft decision value output through the global iterative decoding operation with the termination threshold value stored in the threshold-value storage unit, and for outputting a termination signal indicating termination of the global iterative decoding according to a result of the comparison.
5. The receiver apparatus as claimed in claim 4, wherein the comparison unit performs a termination operation after performing the global iterative decoding when the soft decision value is less than the threshold value, and terminates the global iterative decoding for a corresponding bit when the soft decision value is greater than or equal to the threshold value.
6. The receiver apparatus as claimed in claim 1, wherein the channel decoder comprises a local decoding controller for controlling local iterative decoding for the soft decision value to be performed as many as a predetermined number of times according to global iterative decoding performed by the global decoding controller.
7. The receiver apparatus as claimed in claim 1, further comprising:
a de-interleaver for performing a de-interleaving operation on the soft decision value created by the multi-user detector, and for providing the de-interleaved soft decision value to the channel decoder; and
an interleaver for performing an interleaving operation on the soft decision value feedback from the channel decoder, and for providing the interleaved soft decision value to the multi-user detector.
8. A method for reception control in a multi-user communication system, the method comprising the steps of:
creating a soft decision value for each user signal using a plurality of received signals and information output from a prior iteration of a decoding process;
performing local iterative decoding on the soft decision value, and updating the soft decision value;
controlling local iterative decoding for the soft decision value according to the global iterative decoding; and
checking the updated soft decision value, and controlling whether to perform global iterative decoding.
9. The method as claimed in claim 8, wherein creating a soft decision value comprises:
canceling an interference by applying a parallel interference cancellation scheme to the plurality of received signals, and detecting each user signal component; and
removing an interference component remaining in each user signal.
10. The method as claimed in claim 8, wherein controlling the global iterative decoding comprises:
comparing the soft decision value updated through the local iterative decoding operation with a termination threshold value stored in a threshold-value storage unit;
performing a termination operation after performing global iterative decoding as many as a predetermined number of times when the soft decision value is less than the threshold value; and
terminating global iterative decoding for a corresponding bit when the soft decision value is greater than or equal to the threshold value.
11. The method as claimed in claim 8, wherein a number of the local decoding iterations is determined according to the global iterative decoding.