TDD FDD air interface
First Claim
1. For use in a wireless access network, a TDD FDD system comprising:
- a first base station and a first subscriber unit within a first sector, the first base station transmitting to the first subscriber unit on a downlink frequency during a first time period and the first subscriber unit transmitting to the first base station on an uplink frequency during a second time period following the first time period; and
a second base station and a second subscriber unit within a second sector adjacent to the first sector, the second base station transmitting to the second subscriberunit on the downlink frequency during the second time period and the second subscriber unit transmitting to the second base station on the uplink frequency during the first time period.
5 Assignments
0 Petitions
Accused Products
Abstract
Downlink and uplink frequencies in a wireless access system are time-shared by adjacent sectors, but remain dedicated to downlink or uplink transmission and may utilize FDD-only bandwidth within the MMDS spectrum. TDD wireless access equipment need only be modified by introducing a frequency change at the normal TDD guard point, with respective downlink or uplink periods for adjacent sectors offset to form overlapping frames. Cyclo-stationary processing, block equalization, and burst timing coordination allow the boundary between downlink and uplink portions of both frames to be set dynamically, improving spectral efficiency. Fast frequency switching within an allotted physical slot enables synchronization of time-sharing the dedicated frequencies to be maintained among sectors and cells. Duplex spacing between downlink and uplink frequencies for a given sector and adjacent sectors, combined with in-depth filtering of received signals, prevents spurious out-of-band transmission signal strength from reaching an interference level.
84 Citations
14 Claims
-
1. For use in a wireless access network, a TDD FDD system comprising:
-
a first base station and a first subscriber unit within a first sector, the first base station transmitting to the first subscriber unit on a downlink frequency during a first time period and the first subscriber unit transmitting to the first base station on an uplink frequency during a second time period following the first time period; and
a second base station and a second subscriber unit within a second sector adjacent to the first sector, the second base station transmitting to the second subscriberunit on the downlink frequency during the second time period and the second subscriber unit transmitting to the second base station on the uplink frequency during the first time period. - View Dependent Claims (2, 3, 4)
-
-
5. A transceiver, comprising:
-
means for transmitting or receiving on a first frequency designated for downlink transmission within a first sector during a first time period; and
means for receiving or transmitting on a second frequency different from the first frequency and designated for uplink transmission within the first sector during a second time period following the first time period, wherein the first frequency is employed for downlink transmission during the second time period within a second sector adjacent to the first sector and the second frequency is employed for uplink transmission during the first time period within the second sector. - View Dependent Claims (6, 7, 8, 9)
-
-
10. For use in a wireless access network, a method of time sharing frequencies reserved for FDD operation comprising the steps of:
-
transmitting to a subscriber unit within a first sector during a first time period on a downlink frequency designated for downlink transmission;
receiving from the subscriber unit within the first sector during a second time period following the first time period on an uplink frequency designated for uplink transmission;
transmitting to a subscriber unit within a second sector adjacent to the first sector during the second time period on the downlink frequency; and
receiving from the subscriber unit within the second sector during the first time period on the uplink frequency. - View Dependent Claims (11, 12)
-
-
13. A signal pattern for time sharing frequencies reserved for FDD operation, comprising:
-
downlink transmission to one or more subscribers within a first sector during a first time period on a downlink frequency designated for downlink transmission;
downlink transmission to one or more subscribers within a second sector adjacent the first sector during a second time period following the first time period on the downlink frequency;
uplink transmission from the one or more subscribers within the first sector during the second time period on an uplink frequency designated for uplink transmission; and
uplink transmission from the one or more subscribers within the second sector during the first time period on the uplink frequency, wherein the downlink and uplink transmissions alternate between sectors in sequential time periods on dedicated frequencies. - View Dependent Claims (14)
-
Specification