Digital communication system having improved pilot encoding
First Claim
1. A digital time division multiple access communication system comprising:
- a time slot comprising four quadrature amplitude modulation sub-channels of pre-selected time duration;
a plurality of sync, pilot and data symbols in respective sync, pilot and data symbol positions of each sub-channel, with the pilot symbols arranged in a pre-selected pilot symbol format;
the data symbols modulated according to a pre-selected order of modulation; and
a plurality of dual purpose symbols in respective pilot symbol positions of the pilot symbol format and modulated with an order of modulation less than that of the data symbols, wherein the plurality of dual purpose symbols provide derived pilot symbols and time slot control information.
3 Assignments
0 Petitions
Accused Products
Abstract
A time division multiple access communication system is provided having multiple sub-channels according to known quadrature amplitude modulation techniques. Each sub-channel has a pre-determined time duration and is divided by a pre-determined number of symbol position time divisions. The symbol positions carry color codes and ACP codes in addition to sync, pilot and data symbols. Pilot symbols in the second half of the slot are replaced with dual purpose color code and ACP symbols. The dual purpose symbols are either modulated with a lower order modulation than data symbols or are repeated values of dedicated symbols located earlier in the same slot, or both. Slot throughput is attained with a minimal bit error rate penalty.
-
Citations
36 Claims
-
1. A digital time division multiple access communication system comprising:
-
a time slot comprising four quadrature amplitude modulation sub-channels of pre-selected time duration;
a plurality of sync, pilot and data symbols in respective sync, pilot and data symbol positions of each sub-channel, with the pilot symbols arranged in a pre-selected pilot symbol format;
the data symbols modulated according to a pre-selected order of modulation; and
a plurality of dual purpose symbols in respective pilot symbol positions of the pilot symbol format and modulated with an order of modulation less than that of the data symbols, wherein the plurality of dual purpose symbols provide derived pilot symbols and time slot control information. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A digital time division multiple access communication system comprising:
-
a time slot comprising four quadrature amplitude modulation sub-channels of pre-selected time duration;
a plurality of color code, associated control procedure, sync, pilot and data symbols in respective color code, associated control procedure, sync, pilot and data symbol positions of each sub-channel, with the pilot symbols arranged in a pre-selected pilot symbol format; and
a plurality of dual purpose symbols in respective pilot symbol positions of the pilot symbol format and comprising copies of at least one of the plurality of color code symbols or associated control procedure symbols, wherein the plurality of dual purpose symbols provide derived pilot symbols and time slot control information. - View Dependent Claims (8, 9, 10, 11, 12)
-
-
13. A digital time division multiple access communication system comprising:
-
a time slot comprising four quadrature amplitude modulation sub-channels of pre-selected time duration;
a plurality of color code, associated control procedure, sync, pilot and data symbols in respective sync, pilot and data symbol positions of each sub-channel, with the pilot symbols arranged in a pre-selected pilot symbol format;
the data symbols modulated according to a pre-selected order of modulation; and
a plurality of dual purpose symbols comprising copies of at least one of the plurality of color code symbols or associated control procedure symbols, located in respective pilot symbol positions of the pilot symbol format and modulated with an order of modulation less than that of the plurality of data symbols, wherein the plurality of dual purpose symbols provide derived pilot symbols and time slot control information. - View Dependent Claims (14, 15, 16, 17, 18)
-
-
19. A method of digital time division multiple access communication comprising the steps of:
-
providing a time slot comprising four quadrature amplitude modulation sub-channels of pre-selected time duration;
providing a plurality of color code, associated control procedure, sync, pilot and data symbols in respective sync, pilot and data symbol positions in said time slot, with the pilot symbols arranged in a pre-selected pilot symbol format;
modulating the data symbols with a pre-selected order of modulation;
providing a derived pilot symbol;
modulating the derived pilot symbol with an order of modulation less than that of the data symbols to produce a dual purpose symbol comprising at least one of the plurality of color code symbols or associated control procedure symbols, wherein the dual purpose symbol provide the derived pilot symbol and time slot control information; and
placing the dual purpose symbol in a pre-selected pilot symbol position of the pilot symbol format. - View Dependent Claims (20, 21, 22, 23, 24)
-
-
25. A method of digital time division multiple access communication system comprising the steps of:
-
providing a time slot comprising four quadrature amplitude modulation sub-channels of pre-selected time duration;
providing a plurality of color code, associated control procedure, sync, pilot and data symbols in respective color code, associated control procedure, sync, pilot and data symbol positions in the time slot, with the pilot symbols arranged in a pre-selected pilot symbol format;
copying at least one of the plurality of color code symbols or associated control procedure symbols to provide a dual purpose symbol, wherein the dual purpose symbol provides derived pilot symbol and time slot control information; and
placing the dual purpose symbol in a pre-selected pilot symbol position of the pilot symbol format. - View Dependent Claims (26, 27, 28, 29, 30)
-
-
31. A method of digital time division multiple access communication system comprising the steps of:
-
providing a time slot comprising four quadrature amplitude modulation sub-channels of pre-selected time duration;
providing a plurality of color code, associated control procedure, sync, pilot and data symbols in respective color code, associated control procedure, sync, pilot and data symbol positions in the time slot, with the pilot symbols arranged in a pre-selected pilot symbol format;
modulating the data symbols with a pre-selected order of modulation;
copying at least one of the plurality of color code symbols or associated control procedure symbols to produce a derived pilot symbol;
modulating the derived pilot symbol with an order of modulation less than that of the data symbols to produce a dual purpose symbol, wherein the dual purpose symbol provides the derived pilot symbol and time slot control information; and
placing the dual purpose symbol in a pre-selected pilot symbol position of the pilot symbol format. - View Dependent Claims (32, 33, 34, 35, 36)
-
Specification