1. A removable and adjustable cushioning system for a shoulder strap, the removable and adjustable cushioning system comprising:
a base pad comprising cushioning material and being contoured to conform to a person’s shoulder;
a base shell forming a hard outer covering that is permanently affixed to an upper surface of the base pad;
a plurality of fastener receivers coupled to the base pad via the base shell; and
a fastener removably coupled to at least one of the fastener receivers, the fastener configured to engage the shoulder strap to removably secure the base pad to the shoulder strap,
wherein the fastener is a first fastener and the at least one of the fastener receivers is a first fastener receiver, further comprising a second fastener removably coupled to a second fastener receiver that is spaced from the first fastener receiver, the second fastener configured to removably secure the base pad to the shoulder strap.
2. The removable and adjustable cushioning system of claim 1, wherein the plurality of fastener receivers comprises a plurality of anchor loops, the first fastener receiver comprises a first anchor loop, and the first fastener comprises a retaining strap, further comprising:
a second anchor loop positioned between the first anchor loop and a base pad neck side, wherein the retaining strap, is configured to extend through the first anchor loop, over an upper surface of the shoulder strap, and through the second anchor loop to removably secure the base pad to the shoulder strap.
3. The removable and adjustable cushioning system of claim 2, wherein the first anchor loop and the second anchor loop are substantially parallel, and the first anchor loop and the second anchor loop each extends in a longitudinal direction with respect to the base pad.
4. The removable and adjustable cushioning system of claim 3, wherein the plurality of anchor loops are arranged in a plurality of rows, with each row of the plurality of rows extending in a lateral direction with respect to the base pad, and the plurality of anchor loops are also arranged in a plurality of columns, with each column of the plurality of columns extending in a longitudinal direction with respect to the base pad.
5. The removable and adjustable cushioning system of claim 4, wherein the retaining strap is a first retaining strap, further comprising:
a third anchor loop that is located in a first column that includes the first anchor loop;
a fourth anchor loop that is located in a second column that includes the second anchor loop, with the fourth anchor loop positioned between the third anchor loop and the base pad neck side; and
a second retaining strap that is configured to extend through the third anchor loop, over the upper surface of the shoulder strap, and through the fourth anchor loop to removably secure the base pad to the shoulder strap.
6. The removable and adjustable cushioning system of claim 1, wherein the plurality of fastener receivers are arranged in a plurality of rows, with each row of the plurality of rows extending in a lateral direction with respect to the base pad.
7. A removable and adjustable cushioning system for a shoulder strap, the removable and adjustable cushioning system comprising:
a base pad comprising cushioning material and being contoured to conform to a person’s shoulder;
a base shell forming a hard outer covering that is permanently affixed to an upper surface of the base pad;
a plurality of fastener receivers coupled to the base pad via the base shell;
a fastener removably coupled to at least one of the fastener receivers, the fastener configured to engage the shoulder strap to removably secure the base pad to the shoulder strap; and
a positioning shell removably and replaceably coupled to the base shell, the positioning shell covering and immediately adjacent to substantially an entire surface of the base shell, the positioning shell having a positioning shell neck side and a positioning shell shoulder side substantially opposite to the positioning shell neck side, the positioning shell including the plurality of fastener receivers.
8. The removable and adjustable cushioning system of claim 7, wherein the plurality of fastener receivers comprises a plurality of receiving slots, the at least one of the fastener receivers comprises a first receiving slot, and the fastener comprises a retaining strap, further comprising:
a second receiving slot positioned between the first receiving slot and the positioning shell neck side, wherein the retaining strap is configured to extend under the positioning shell, upwardly through the first receiving slot and the second receiving slot, and over an upper surface of the shoulder strap to removably secure the positioning shell and the base pad to the shoulder strap.
9. The removable and adjustable cushioning system of claim 8, wherein the first receiving slot and the second receiving slot are substantially parallel and the first receiving slot and the second receiving slot each extends in a longitudinal direction with respect to the positioning shell.
10. The removable and adjustable cushioning system of claim 9, wherein the plurality of receiving slots are arranged in a plurality of rows, with each row of the plurality of rows extending in a lateral direction with respect to the positioning shell, and the plurality of receiving slots are also arranged in a plurality columns, with each column of the plurality of columns extending in a longitudinal direction with respect to the positioning shell.
11. The removable and adjustable cushioning system of claim 10, wherein the retaining strap is a first retaining strap, further comprising:
a third receiving slot that is located in a first column that includes the first receiving slot;
a fourth receiving slot that is located in a second column that includes the second receiving slot, with the fourth receiving slot positioned between the third receiving slot and the positioning shell neck side; and
a second retaining strap that is configured to extend under the positioning shell, upwardly through the third receiving slot and the fourth receiving slot, and over the upper surface of the shoulder strap to removably secure the positioning shell and the base pad to the shoulder strap.
12. The removable and adjustable cushioning system of claim 11, wherein the first retaining strap and the second retaining strap each comprises a first end that may be removably affixed to a second end.
13. The removable and adjustable cushioning system of claim 7, wherein the positioning shell includes a positioning shell neck notch formed in the positioning shell neck side, and the base pad includes a base pad neck notch formed in a base pad neck side, the base pad neck notch located substantially adjacent to the positioning shell neck notch.
14. The removable and adjustable cushioning system of claim 7, wherein the plurality of fastener receivers comprises a plurality of apertures in the positioning shell that are distributed about the positioning shell.
15. A removable and adjustable cushioning system for a shoulder strap, the removable and adjustable cushioning system comprising:
a base pad comprising cushioning material and being contoured to conform to a person’s shoulder;
a positioning shell removably coupled to the base pad, the positioning shell comprising a row of receiving slots and a position adjustment slot intersecting the receiving slots;
a post having a proximal end that is adjacent to a lower surface of the positioning shell and a distal end that is configured to extend through a first receiving slot in the row of receiving slots andor through the position adjustment slot, the distal end also configured to protrude through the shoulder strap; and
a cap that is removably received by the distal end of the post to removably secure the shoulder strap to the positioning shell and the base pad, whereby the post may be moved from the first receiving slot to a second receiving slot via the position adjustment slot.
16. The removable and adjustable cushioning system of claim 15, wherein the row of receiving slots is a first row of receiving slots, further comprising:
a second row of receiving slots spaced from the first row of receiving slots, the second row of receiving slots comprising a third receiving slot and a fourth receiving slot; and
a retaining strap that is configured to extend under the positioning shell, upwardly through the third receiving slot and the fourth receiving slot, and over an upper surface of the shoulder strap to removably secure the positioning shell and the base pad to the the shoulder strap.
17. The removable and adjustable cushioning system of claim 16, wherein the positioning shell includes a positioning shell neck side and a positioning shell shoulder side substantially opposite to the positioning shell neck side, the positioning shell further including a positioning shell neck notch formed in the positioning shell neck side, and the base pad including a base pad neck notch formed in a base pad neck side, the base pad neck notch located substantially adjacent to the positioning shell neck notch.
18. A removable and adjustable cushioning system for a shoulder strap, the removable and adjustable cushioning system comprising:
a base pad comprising cushioning material and being contoured to conform to a person’s shoulder;
a plurality of fastener receivers coupled to the base pad;
a fastener removably coupled to at least one of the fastener receivers, the fastener configured to engage the shoulder strap to removably secure the base pad to the shoulder strap; and
a positioning shell removably coupled to the base pad, the positioning shell having a positioning shell neck side and a positioning shell shoulder side substantially opposite to the positioning shell neck side, the positioning shell including the plurality of fastener receivers,
wherein the fastener comprises a post having a distal end that is configured to extend through one of the fastener receivers and to protrude through the shoulder strap, and further including a cap that is removably received by the distal end of the post, the cap configured to removably secure the shouder strap to the positioning shell and the base pad.
19. A removable and adjustable cushioning system for a shoulder strap, the removable and adjustable cushioning system comprising:
a base pad comprising cushioning material and being contoured to conform to a person’s shoulder;
a positioning shell coupled to the base pad, the positioning shell having a positioning shell neck side and a positioning shell shoulder side substantially opposite to the positioning shell neck side;
a first fastening assembly coupled to the positioning shell for engaging the shoulder strap to removably secure the positioning shell and the base pad to the shoulder strap, the first fastening assembly comprising:
a first arm rotatably coupled to the positioning shell, the first arm including a first plurality of hooks;
a first lever rotatably coupled to the positioning shell and spaced from the first arm; and
a first bale rotatably coupled to the first lever and configured to be received by one of the first plurality of hooks; and
a second fastening assembly coupled to the positioning shell and spaced from the first fastening assembly, the second fastening assembly for engaging the shoulder strap to removably secure the positioning shell and the base pad to the shoulder strap, the second fastening assembly comprising:
a second arm rotatably coupled to the positioning shell, the second arm including a second plurality of hooks;
a second lever rotatably coupled to the positioning shell and spaced from the second arm; and
a second bale rotatably coupled to the second lever and configured to be received by one of the second plurality of hooks.
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 constructing a family of low-density-parity-check (LDPC) codes, the method comprising:
identifying a code rate for an LDPC code in the family;
identifying a protograph for the LDPC code; and
constructing a base matrix for the LDPC code, the base matrix constructed by:
replacing each zero in the protograph with a \u2018\u22121\u2019;
selecting a corresponding value for an absolute shift for each one in the protograph based on constraining a number of relative shifts per column of the LDPC code to one and increasing a size of a smallest cycle in a graph of the LDPC code; and
replacing each one in the protograph with the corresponding value.
2. The method of claim 1, wherein determining the protograph for the LDPC code comprises:
calculating a number of variable nodes for the protograph based on utilization of a critical path of check nodes in the protograph.
3. The method of claim 1, wherein determining the protograph for the LDPC code comprises:
setting a column weight of less than or equal to four for each code rate in the family of LDPC codes, wherein LDPC codewords encoded using the family of LDPC codes are decodable in three or four layers.
4. The method of claim 1, wherein the LDPC code has a length of 432 bits and further comprising:
constructing a 1728-bit length LDPC code having the code rate by lifting the base matrix for the LDPC code of length 432 by a lifting factor of four.
5. The method of claim 4, wherein constructing the 1728-bit length LDPC code comprises:
cyclically shifting one or more absolute shift values in the lifted base matrix to increase minimum distance and reduce a number of cycles having a smallest size in a graph of the 1728-bit length LDPC code.
6. The method of claim 1, wherein constructing the base matrix for the LDPC code further comprises:
constructing the base matrix such that permutation of columns in the base matrix results in a similar code error performance.
7. The method of claim 1, wherein determining the protograph for the LDPC code comprises:
identifying a parallelization factor based on a balance between parallel processing of layers in the base matrix and sharing of information between parity checks in the processing of the layers in the base matrix.
8. The method of claim 7, wherein the LDPC code is a first LDPC code and further comprising:
determining a second protograph for second LDPC code in the family having a second code rate; and
lifting the second protograph using a same set of relative shift values from the base matrix for the first LDPC code, wherein each LDPC code in the family of LDPC codes have different code rates and a common set of circulant permutations.
9. The method of claim 8, wherein code rates of the LDPC codes in the family include rate-\u215c code, rate-\xbd code, rate-\u215d code, rate-\xbe code, and rate- 1316 code and wherein the parallelization factor is 27.
10. The method of claim 1 further comprising:
transmitting a codeword encoded using the base matrix of the LDPC code in a millimeter-wave wireless communications network.
11. A decoder configured to decode a low-density-parity-check (LDPC) codeword, the decoder comprising:
a storage device configured to receive the LDPC codeword; and
a check node processor configured to decode the LDPC codeword by iteratively processing layers of an LDPC code constructed by:
identifying a protograph for the LDPC code; and
constructing a base matrix for the LDPC code, the base matrix constructed by:
replacing each zero in the protograph with a \u2018\u22121\u2019;
selecting a corresponding value for an absolute shift for each one in the protograph based on constraining a number of relative shifts per column of the LDPC code to one and increasing a size of a smallest cycle in a graph of the LDPC code; and
replacing each one in the protograph with the corresponding value.
12. The decoder of claim 11 further comprising:
a number of variable nodes, wherein the number of variable nodes is selected based on utilization of a critical path in the check node processor.
13. The decoder of claim 11, wherein the check node processor further configured to decode the LDPC codeword by iteratively processing the LDPC code in three or four layers.
14. The decoder of claim 11 further comprising:
a shift module configured to apply a single relative-shift to layers of the LDPC code being processed.
15. The decoder of claim 11, wherein the LDPC code has a length of one of 432-bits and 1728-bits, wherein the base matrix is constructed using a parallelization factor of 27, wherein the LDPC code is part of a family of LDPC codes, and wherein code rates of the LDPC codes in the family include rate-\u215c code, rate-\xbd code, rate-\u215d code, rate-\xbe code, and rate- 1316 code.
16. A method for constructing a low-rate low-density-parity-check (LDPC) code, the method comprising:
concatenating a number of information bits with a number of zeros to form a set of concatenated bits;
encoding the concatenated bits using an encoder configured to encode LDPC codewords having a code rate that is larger than a code rate of the low-rate LDPC code to form an LDPC codeword; and
replacing the zeros in the LDPC codeword with the information bits.
17. The method of claim 16, wherein replacing the zeros in the LDPC codeword with the information bits comprises:
replacing the zeros with one copy of the information bits, wherein the number of the information bits and the number of zeros are equal, wherein the encoder is configured to encode LDPC codewords having a code rate that is twice the code rate of the low-rate LDPC code, wherein the low-rate LDPC code has a code rate of one of \xbc-rate and 316-rate, and wherein the low-rate LDPC code is constructed from high-rate LDPC code having a code rate of one of \xbd-rate and \u215c-rate.
18. The method of claim 16, wherein replacing the zeros in the LDPC codeword with the information bits comprises:
replacing the zeros with three copies of the information bits, wherein the number of zeros is three times the number of the information bits, wherein the encoder is configured to encode LDPC codewords having a code rate that is four times the code rate of the low-rate LDPC code, wherein the low-rate LDPC code has a code rate of one of \u215b-rate, and wherein the low-rate LDPC code is constructed from high-rate LDPC code having a code rate of one of \xbd-rate.
19. The method of claim 16 further comprising:
responsive to identifying poor channel conditions, increasing a power of a received signal by decreasing a code rate of a transmitted LDPC codeword.
20. The method of claim 16, wherein the low-rate LDPC code has a length of one of 432-bits and 1728-bits, wherein the low-rate LDPC code is part of a family of low-rate LDPC codes, and wherein code rates of the low-rate LDPC codes in the family include rate-\u215b code, rate- 316 code, and rate-\xbc code.