1. A golf club head comprising:
a club head body having a front face with a recess therein;
an insert disposed within the recess, the insert comprising a body with an exterior surface, an interior surface and a perimeter defining the thickness of the body, the insert composed of a thermoplastic polyurethane material formed from a polytetramethylene ether glycol terminated hexamethylene diisocyanate prepolymer having a nitrogen-carbon-oxygen group content of 8% to 12%, and a 1,4 butane diol, wherein the insert has a Shore D hardness ranging from 50 to 65, a thickness ranging from 0.125 inch to 0.500 inch, a heat deflection less than 1% after loading of 14 pounds per square inch at a temperature of 200\xb0 F. for two hours, and a change in ultraviolet light stability of less than 1% after an exposure time of 48 hours;
wherein the insert has a \u201cL\u201d color value of approximately 95 on a scale of 0 to 100.
2. The golf club head according to claim 1 wherein the insert has a thickness ranging from 0.188 inch to 0.200 inch.
3. The golf club head according to claim 1 further comprising an epoxy adhesive applied to the interior surface of the insert to attach the insert to the golf club head.
4. The golf club head according to claim 1 wherein the club head body is composed of a stainless steel material.
5. The golf club head according to claim 1 wherein the golf club head is a putter-type head.
6. The golf club head according to claim 1 wherein the insert has a trapezoidal shape.
7. The golf club head according to claim 1 wherein the depth of the recess is greater than the thickness of the insert.
8. The golf club head according to claim 1 wherein the insert is between 10 to 25 percent of the volume of the club head.
9. The golf club head according to claim 1 wherein the insert is between 1 to 5 percent of the mass of the club head.
10. The golf club head according to claim 1 wherein the insert is between 55 to 75 percent of the area of the face of the club head.
11. The golf club head according to claim 1 wherein the golf club head is an iron-type head.
12. The golf club head according to claim 1 wherein the golf club head is a wood-type head.
13. A putter-type club head comprising:
a club head body composed of a stainless steel material comprising a front face, a toe to one side of the front face and a heel to the other side of the front face, and a sole, the front face having a recess therein, the recess defined by a frontal recess wall and an edge wall substantially perpendicular to the frontal recess wall, the edge wall defining the depth and area of the recess;
an insert disposed within the recess, the insert comprising a body with an exterior surface, an interior surface and a perimeter defining the thickness of the body, the insert composed of a thermoplastic polyurethane material formed from a polytetramethylene ether glycol terminated hexamethylene diisocyanate prepolymer and a 1,4 butane diol, wherein the insert has a Shore D hardness ranging from 50 to 65, a heat deflection less than 1% after loading of 14 pounds per square inch at a temperature of 200\xb0 F. for two hours, and a change in ultraviolet light stability of less than 1% after an exposure time of 48 hours.
wherein the insert has a \u201cL\u201d color value of approximately 95 on a scale of 0 to 100.
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 for an efficient telecommunications receiver system for accurately decoding a received composite signal having data signal and pilot signal components comprising:
receiving said composite signal and extracting a pilot signal and a data signal therefrom;
calculating a log-likelihood ratio as a function of a channel estimate based on said pilot signal; and
scaling said log-likelihood ratio by a predetermined log-likelihood ratio scaling factor and providing an accurate log-likelihood value in response thereto and computing a primary carrier signal-to-interference ratio; and
decoding said received composite signal based on said accurate log-likelihood value and said data signal.
2. The method of claim 1 wherein said pilot signal and said data signal comprise pilot samples and data samples, respectively.
3. The method of claim 1 further comprising despreading said received composite signal in accordance with a predetermined spreading function and providing a despread signal in response thereto.
4. A method for providing an accurate log-likelihood value to improve receiver performance for a wireless communications system, comprising:
extracting a pilot signal and a data signal from a received composite signal;
computing a carrier signal-to-interference ratio based on said pilot signal and said data signal and providing a first signal-to-interference ratio and a second signal-to-interference ratio based in response thereto;
computing a log-likelihood ratio scaling factor based on said first signal-to-interference ratio and said second signal-to-interference ratio;
calculating a log-likelihood ratio as a function of a channel estimate based on said pilot signal; and
scaling said log-likelihood ratio by said log-likelihood ratio scaling factor and providing said accurate log-likelihood value in response thereto.
5. A method for increasing a signal-to-noise ratio of a receiver employing reference symbol aided demodulation, comprising:
combining information from a reference signal transmitted over a channel with information from a corresponding known transmitted reference signal to obtain an estimate of said channel over which said reference symbol is transmitted by a transmitter and received by said receiver;
calculating a log-likelihood ratio estimate for a data signal received by said receiver over said channel, said log-likelihood ratio estimate being a function of said received data signal, said channel estimate, and a noise variance of said signal;
applying a scaling factor to said log-likelihood ratio estimate to provide an accurate log-likelihood ratio, said scaling factor based on a noise variance of said channel estimate, said noise variance of said data signal, and an average of received energy per bit in said data signal; and
employing said accurate log-likelihood value to demodulate said received data signal.
6. A method for a communication system employing pilot assisted coherent demodulation, comprising:
encoding a data signal in accordance with a Turbo code and transmitting said data signal with a pilot signal;
receiving said data signal and said pilot signal and providing an estimate of said channel based on said received pilot signal based on a turbo decoding and a priori knowledge of said pilot signal;
generating an accurate log-likelihood ratio that is a function of a noise variance of said data signal, a noise variance of said estimate of said channel, an average received energy per information bit included in said data signal, and said data signal; and
employing said log-likelihood ratio as a metric to demodulate said received data signal.