Frame structure for an adaptive modulation wireless communication system
View Patent ↗A method of simplifying the encoding of a predetermined number of bits of data into frames including adding error coding bits so that a ratio of the frame length times the baud rate of the frame times he bit packing ratio of the data divided the total bits of data is always an integer. The method may also convolutionally encode the bits of data so that the same equation is also always an integer.
1. A method of operating an on-demand wireless cellular communication system for exchanging information between a base station and a plurality of mobile cellular phones, comprising:
at the base station:
allocate downlink transmission resources to one or more receiving mobile cellular phones in downlink time slots of a frame, and allocate uplink transmission resources to one or more transmitting mobile cellular phones in uplink time slots of the frame;
determine per mobile cellular phone uplink modulation schemes for the uplink time slots and per mobile cellular phone downlink modulation schemes for the downlink time slots;
encode downlink data addressed to the one or more receiving mobile cellular phones according to a respective determined downlink modulation scheme and transmit the encoded downlink data in the downlink time slots;
receive the uplink time slots with encoded uplink data from the one or more transmitting mobile cellular phones and decode the encoded uplink data according to a respective determined uplink modulation scheme;
encode control information using a least complex modulation scheme available in the wireless cellular communication system for control information, the control information providing the determined downlink modulation schemes for the one or more receiving mobile cellular phones and the determined uplink modulation schemes for the one or more transmitting mobile cellular phones; and
transmit the encoded control information to the plurality of mobile cellular phones;
at a receiving mobile cellular phone:
receive the control information, receive the downlink encoded data addressed to the receiving mobile cellular phone in the downlink time slots, and decode the downlink encoded data based on the respective determined downlink modulation scheme; and
at a transmitting mobile cellular phone:
receive the control information, encode the uplink data based on the respective determined uplink modulation scheme, and transmit the encoded uplink data to the base station in the uplink time slots.
2. A method as claimed in claim 1 , wherein the control information includes identification of the downlink data allocated in the downlink time slots to the one or more receiving mobile cellular phones.
3. A method as claimed in claim 1 , wherein the control information includes identification of the uplink data allocated in the uplink time slots to the one or more transmitting mobile cellular phones.
4. A method as claimed in claim 1 , wherein a downlink modulation scheme used for encoding downlink data for the receiving mobile cellular phone in the downlink time slots can be different from a downlink modulation scheme used for encoding downlink data to another receiving mobile cellular phone in the downlink time slots.
5. A method as claimed in claim 1 , wherein an uplink modulation scheme used at the transmitting mobile cellular phone for encoding uplink data in the uplink time slots, can be different from an uplink modulation scheme used by another transmitting mobile cellular phone for encoding uplink data in the uplink time slots.
6. A method as claimed in claim 1 , wherein a downlink modulation scheme used for encoding downlink data for the receiving mobile cellular phone in the downlink time slots, can be different from a downlink modulation scheme used for encoding downlink data for the receiving mobile cellular phone in subsequent downlink time slots.
7. A method as claimed in claim 1 , wherein an uplink modulation scheme used by the transmitting mobile cellular phone for encoding uplink data in the uplink time slots can be different from an uplink modulation scheme used by the transmitting mobile cellular phone for encoding uplink data in subsequent uplink time slots.
8. A method as claimed in claim 1 , wherein the per mobile cellular phone downlink modulation schemes are dynamically adapted according to one or more of: channel interference determined at the receiving mobile cellular phone for a downlink established to the receiving mobile cellular unit, and a maximum error level for the downlink.
9. A method as claimed in claim 8 , wherein a per mobile cellular phone downlink modulation scheme is further determined based on the modulation schemes supported by the receiving mobile cellular phone.
10. A method as claimed in claim 1 , wherein the per mobile cellular phone uplink modulation schemes are dynamically adapted according to one or more of: channel interference determined at the base station for an uplink established from the transmitting mobile cellular phone, and a maximum error level for the uplink.
11. A method as claimed in claim 10 , wherein a per mobile cellular phone uplink modulation scheme is further determined based on the modulation schemes supported by the transmitting mobile cellular phone.
12. A method as claimed in claim 1 , wherein the base station further encodes the downlink data addressed to the receiving mobile cellular phone using a forward error correction scheme.
13. A method as claimed in claim 12 , wherein the forward error correction scheme adds a number of error correction bits to the downlink data.
14. A method as claimed in claim 13 , wherein the number of the error correction bits is determined based on a minimum error rate for the downlink data.
15. A method as claimed in claim 12 , wherein the number of the error correction bits is determined dynamically based on a minimum error rate for the downlink data, the downlink resources allocated to the receiving mobile cellular phone in the downlink time slots, and the downlink modulation scheme used by the base station for encoding the downlink data addressed to the receiving mobile cellular phone.
16. A method as claimed in claim 13 , wherein the error correction bits added to the downlink data include convolutional encoding bits.
17. A method as claimed in claim 1 , wherein the transmitting mobile cellular phone further encodes the uplink data addressed to the base station by using a forward error correction scheme.
18. A method as claimed in claim 17 , wherein the forward error correction scheme adds a number of error correction bits to the uplink data.
19. A method as claimed in claim 18 , wherein the number of the error correction bits is determined based on a minimum error rate for the uplink data.
20. A method as claimed in claim 18 , wherein the number of the error correction bits is determined dynamically based on a minimum error rate for the uplink data, the uplink resources allocated to the transmitting mobile cellular phone in the uplink time slots, and the uplink modulation scheme used by the transmitting mobile cellular phone for encoding the uplink data addressed to the base station.