System and method for increasing cellular system capacity by the use of the same frequency and time slot for both uplink and downlink transmissions

• US 7,096,042 B2
• Filed: 07/22/2003
• Issued: 08/22/2006
• Est. Priority Date: 01/21/2003
• Status: Expired due to Fees

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Marinier, Paul
• Primary Examiner(s): Feild, Joseph
• Assistant Examiner(s): Afshar, Kamran
• Application Number:
  US10/624,812
• Publication Number:
  US 20040142700A1
• Time in Patent Office: 1,127 Days
• Field of Search: 455/450, 455/453, 455/464, 455/509, 455/562.1, 455/24, 455/278.1, 455/63.1, 455/69, 370/278, 370328-347
• US Class Current: 455/562.1
• CPC Class Codes: H01Q 3/2611 Means for null steering; Adaptive interference nulling
• CPC Class Codes: H04B 1/525 with means for reducing leakage of transmitter signal into the receiver
• CPC Class Codes: H04B 7/04 using two or more spaced independent antennas

Abstract

A method for increasing cellular system capacity includes receiving a signal in a time slot and a frequency band and transmitting a signal in the same time slot and the same frequency band. An adaptive self-interference canceller is used to reduce the radio frequency self-interference created by receiving and transmitting signals in the same time slot and the same frequency band. The self-interference can be further reduced by using: (1) a circulator connected between an antenna, a receiver, and a transmitter; (2) separate antennas for receiving and transmitting signals can be used; and/or (3) an adaptive antenna.

Claims

1. A method for increasing cellular system capacity, comprising the steps of:

receiving a signal in a time slot in a frequency band;

transmitting a signal simultaneously with said received signal in the same time slot and frequency band;

using an adaptive self-interference canceller to reduce the radio frequency self-interference created by receiving and transmitting signals in the time slot; and

using a circulator, the circulator being connected between an antenna, a receiver, and a transmitter.

2. The method according to claim 1, wherein the circulator acts to reduce radio frequency self-interference by isolating the signal flow between the antenna and the receiver or between the transmitter and the antenna.

3. The method according to claim 1, further comprising the step of using separate antennas for receiving and transmitting.

4. The method according to claim 1, further comprising the step of using an adaptive antenna.

5. The method according to claim 1, wherein the canceller acts to reduce baseband self-interference by subtracting the self-interference from the rest of a received signal.

6. A system for increasing cellular system capacity, comprising:

an antenna;

a receiver section connected to said antenna, said receiver section receiving a signal;

a transmitter section connected to said antenna, said transmitter section transmitting a signal;

an adaptive self-interference canceller connected between said receiver section and said transmitter section, said adaptive self-interference canceller reducing radio frequency self-interference created when said receiver section receives a signal and said transmitter section simultaneously transmits a signal in the same time slot and the same frequency band; and

a circulator connected between said antenna, said receiver section, and said transmitter section.

7. The system according to claim 6, wherein said antenna comprises an adaptive antenna.

8. The system according to claim 6, wherein said antenna comprises a single antenna for receiving and transmitting signals.

9. The system according to claim 6, wherein said antenna comprises an antenna array for receiving and transmitting signals.

10. The system according to claim 6, wherein said antenna comprises a first antenna for receiving signals and a second antenna for transmitting signals.

11. The system according to claim 6, wherein said antenna comprises a first antenna array for receiving signals and a second antenna array for transmitting signals.