Dual channel time division duplex (TDD) communication
A system and method to use existing Long Term Evolution (LTE) and Worldwide Interoperability for Microwave Access (WiMAX) based signaling to effectuate dual-channel Time Division Duplex (TDD) communication between two transceivers giving preference to one type of subframes (either downlink or uplink) for data transmission. In backhaul communications between pico (or femto) and macro base stations, using LTE and WiMAX's TDD mode in such a manner effectively reduces unnecessary transmissions of pilot and synchronization sequence in downlink signaling, thereby reducing the level of pilot overhead and minimizing interference when data is not being transmitted. Similarly, the use of existing LTE (or WiMAX) implementations of TDD radio frames in this manner may achieve radio silence for some duration (e.g., when no uplink sub-frames are transmitted) when operating in a license-exempt spectrum, thereby allowing other license-exempt devices to potentially share the radio channel during the silence period.
1. A method of wirelessly transmitting data between a first transceiver and a second transceiver, the method comprising:
establishing a first Time Division Duplex (TDD) connection between the first and second transceivers on a first carrier frequency;
establishing a second TDD connection between the first and second transceivers on a second carrier frequency,
selecting by the first transceiver, subframes for transmitting the data to the second transceiver during a single radio frame duration, wherein the subframes are selected from:
a first set of subframes in the first TDD connection, wherein the first set of subframes is designated for downlink transmission in the first TDD connection, and
a second set of subframes in the second TDD connection, wherein the second set of subframes is designated for uplink transmission in the second TDD connection;
transmitting the data from the first transceiver to the second transceiver utilizing the subframes selected from both the first and second sets of subframes;
selecting by the second transceiver, subframes from at least one set of subframes for transmitting the data to the first transceiver during a single radio frame duration, wherein the subframes are selected by the second transceiver from:
a third set of subframes in the first TDD connection, wherein the third set of subframes is designated for uplink transmission in the first TDD connection, and
a fourth set of subframes in the second TDD connection, wherein the fourth set of subframes is designated for downlink transmission in the second TDD connection; and
transmitting the data from the second transceiver to the first transceiver utilizing the selected subframes;
wherein the method further comprises at least one of the following:
setting up a third TDD connection between a third transceiver and a fourth transceiver on the first carrier frequency, wherein uplink and downlink subframes in the third TDD connection are synchronized with corresponding subframes in the third and the first sets of subframes in the first TDD connection during the single radio frame duration; and
setting up a fourth TDD connection between the third and the fourth transceivers on the second carrier frequency, wherein uplink and downlink subframes in the fourth TDD connection are synchronized with corresponding subframes in the second and the fourth sets of subframes in the second TDD connection during the single radio frame duration.
2. A method of wirelessly transmitting data between a first transceiver and a second transceiver, the method comprising:
establishing a first Time Division Duplex (TDD) connection between the first and second transceivers on a first carrier frequency;
establishing a second TDD connection between the first and second transceivers on a second carrier frequency;
selecting by the first transceiver, subframes for transmitting the data to the second transceiver during a single radio frame duration, wherein the subframes are selected from:
a first set of subframes in the first TDD connection, wherein the first set of subframes is designated for downlink transmission in the first TDD connection, and
a second set of subframes in the second TDD connection, wherein the second set of subframes is designated for uplink transmission in the second TDD connection;
transmitting the data from the first transceiver to the second transceiver utilizing the subframes selected from both the first and second sets of subframes;
selecting by the second transceiver, subframes from at least one set of subframes for transmitting the data to the first transceiver during a single radio frame duration, wherein the subframes are selected by the second transceiver from:
a third set of subframes in the first TDD connection, wherein the third set of subframes is designated for uplink transmission in the first TDD connection, and
a fourth set of subframes in the second TDD connection, wherein the fourth set of subframes is designated for downlink transmission in the second TDD connection; and
transmitting the data from the second transceiver to the first transceiver utilizing the selected subframes;
wherein the method further comprises at least one of the following:
setting up a third TDD connection between a third transceiver and a fourth transceiver on the first carrier frequency, wherein uplink and downlink subframes in the third TDD connection are asynchronous with corresponding subframes in the third and the first sets of subframes in the first TDD connection during the single radio frame duration; and
setting up a fourth TDD connection between the third and the fourth transceivers on the second carrier frequency, wherein uplink and downlink subframes in the fourth TDD connection are asynchronous with corresponding subframes in the second and the fourth sets of subframes in the second TDD connection during the single radio frame duration.
3. A method of wirelessly transmitting data between a first transceiver and a second transceiver, the method comprising:
establishing a first Time Division Duplex (TDD) connection between the first and second transceivers on a first carrier frequency;
establishing a second TDD connection between the first and second transceivers on a second carrier frequency;
selectins by the first transceiver, subframes for transmitting the data to the second transceiver during a single radio frame duration, wherein the subframes are selected from:
a first set of subframes in the first TDD connection, wherein the first set of subframes is designated for downlink transmission in the first TDD connection, and
a second set of subframes in the second TDD connection, wherein the second set of subframes is designated for uplink transmission in the second TDD connection;
transmitting the data from the first transceiver to the second transceiver utilizing the subframes selected from both the first and second sets of subframes;
selecting by the second transceiver, subframes from at least one set of subframes for transmitting the data to the first transceiver during a single radio frame duration, wherein the subframes are selected by the second transceiver from:
a third set of subframes in the first TDD connection, wherein the third set of subframes is designated for uplink transmission in the first TDD connection, and
a fourth set of subframes in the second TDD connection, wherein the fourth set of subframes is designated for downlink transmission in the second TDD connection;
transmitting the data from the second transceiver to the first transceiver utilizing the selected subframes;
using a third transceiver, transmitting data to a fourth transceiver using a fifth set of subframes in a third TDD connection established between the third and the fourth transceivers on the first carrier frequency, wherein the subframes in the fifth set of subframes are designated for downlink transmission in the third TDD connection; and
using the third transceiver, transmitting data to the fourth transceiver using a sixth set of subframes in a fourth TDD connection established between the third and the fourth transceivers on the second carrier frequency, wherein the subframes in the sixth set of subframes are designated for uplink transmission in the fourth TDD connection,
wherein one of the following applies:
the third transceiver transmits data to the fourth transceiver using the subframes in the sixth set of subframes during the single radio frame duration only when the subframes in the fifth set of subframes during the single radio frame duration are insufficient to accommodate data to be sent from the third transceiver during the single radio frame duration, and
the third transceiver transmits data to the fourth transceiver using the subframes in the fifth set of subframes during the single radio frame duration only when the subframes in the sixth set of subframes during the single radio frame duration are insufficient to accommodate data to be sent from the third transceiver during the single radio frame duration.
4. The method of claim 3 , further comprising:
using the fourth transceiver, performing one of the following:
transmitting data to the third transceiver using a seventh set of subframes in the third TDD connection and an eighth set of subframes in the fourth TDD connection, wherein the subframes in the seventh set of subframes are designated for uplink transmission in the third TDD connection and the subframes in the eighth set of subframes are designated for downlink transmission in the fourth TDD connection, wherein the subframes in the seventh set of subframes are used for data transmission during the single radio frame duration only when the subframes in the eighth set of subframes during the single radio frame duration are insufficient to accommodate data to be sent from the fourth transceiver during the single radio frame duration; and
transmitting data to the third transceiver using the seventh set of subframes in the third TDD connection and the eighth set of subframes in the fourth TDD connection, wherein the subframes in the eighth set of subframes are used for data transmission during the single radio frame duration only when the subframes in the seventh set of subframes during the single radio frame duration are insufficient to accommodate data to be sent from the fourth transceiver during the single radio frame duration.
5. A method of wirelessly transmitting data between a first transceiver and a second transceiver, the method comprising:
establishing a first Time Division Duplex (TDD) connection between the first and second transceivers on a first carrier frequency;
establishing a second TDD connection between the first and second transceivers on a second carrier frequency;
selecting by the first transceiver, subframes for transmitting the data to the second transceiver during a single radio frame duration, wherein the subframes are selected from:
a first set of subframes in the first TDD connection, wherein the first set of subframes is designated for downlink transmission in the first TDD connection, and
a second set of subframes in the second TDD connection, wherein the second set of subframes is designated for uplink transmission in the second TDD connection;
transmitting the data from the first transceiver to the second transceiver utilizing the subframes selected from both the first and second sets of subframes;
selecting by the second transceiver, subframes from at least one set of subframes for transmitting the data to the first transceiver during a single radio frame duration, wherein the subframes are selected by the second transceiver from:
a third set of subframes in the first TDD connection, wherein the third set of subframes is designated for uplink transmission in the first TDD connection, and
a fourth set of subframes in the second TDD connection, wherein the fourth set of subframes is designated for downlink transmission in the second TDD connection;
transmitting the data from the second transceiver to the first transceiver utilizing the selected subframes;
setting up a third TDD connection between the first and the second transceivers on a third carrier frequency that is different from the first and the second carrier frequencies; and
performing one of the following:
configuring the first transceiver to send data to the second transceiver using the first set of subframes in the first TDD connection, the second set of subframes in the second TDD connection, and a fifth set of subframes in the third TDD connection, and configuring the second transceiver to send data to the first transceiver using the third set of subframes in the first TDD connection, the fourth set of subframes in the second TDD connection, and a sixth set of subframes in the third TDD connection, wherein subframes in the fifth set of subframes are designated for downlink transmission in the third TDD connection and subframes in the sixth set of subframes are designated for uplink transmission in the third TDD connection, and
configuring the second transceiver to send data to the first transceiver using the fourth set of subframes in the second TDD connection, the fifth set of subframes in the third TDD connection, and the third set of subframes in the first TDD connection, and configuring the first transceiver to send data to the second transceiver using the first set of subframes in the first TDD connection, the second set of subframes in the second TDD connection, and the sixth set of subframes in the third TDD connection.