Co-channel wireless communication methods and systems using relayed wireless communications

• US 8,108,004 B2
• Filed: 03/01/2010
• Issued: 01/31/2012
• Est. Priority Date: 03/24/2003
• Status: Active Grant

• Current Assignee: ATC Technology Corporation (FedEx Corporation)
• Original Assignee: ATC Technology Corporation (FedEx Corporation)
• Inventors: Karabinis, Peter D.
• Primary Examiner(s): Sobutka, Philip
• Application Number:
  US12/714,789
• Publication Number:
  US 20100157929A1
• Time in Patent Office: 701 Days
• Field of Search: None
• US Class Current: 455/562.1
• CPC Class Codes: H04B 7/026 Co-operative diversity, e.g. using fixed or mobile stations as relays
• CPC Class Codes: H04B 7/0491 using two or more sectors, i.e. sector diversity
• CPC Class Codes: H04B 7/0837 using pre-detection combining H04B7/0868 takes precedence
• CPC Class Codes: H04B 7/0854 using error minimizing algorithms, e.g. minimum mean squared error [MMSE], "cross-correlation" or matrix inversion
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity
• CPC Class Codes: H04B 7/18584 Arrangements for data networking, i.e. for data packet routing, for congestion control data switching networks H04L12/00
• CPC Class Codes: H04W 52/38 TPC being performed in particular situations
• CPC Class Codes: H04W 52/42 in systems with time, space, frequency or polarisation diversity

Abstract

Wireless communications are transmitted from at least two radioterminals to a base station co-channel over a return link using a return link alphabet. Wireless communications are also transmitted from the base station to the at least two radioterminals over a forward link using a forward link alphabet that has more symbols than the return link alphabet. The co-channel signals are deciphered at the receiver, while the radioterminals can use a smaller return link alphabet, which can reduce the power dissipation at the radioterminals.

Claims

1. A wireless communications method comprising:

receiving first and second wireless co-channel communications, at each element, of a plurality of elements, of an antenna that is associated with a sector of a base station, from respective first and second physically distinct radioterminals; and

processing a respective plurality of signals, that is provided by the plurality of elements of the antenna that is associated with the sector of the base station, to recover data;

wherein receiving first and second wireless co-channel communications, at each element, of a plurality of elements, of an antenna that is associated with a sector of a base station, from respective first and second physically distinct radioterminals comprises;

receiving first and second signals, from the respective first and second physically distinct radioterminals, at each element, of the plurality of elements, of the antenna that is associated with the sector of the base station;

the first and second signals overlapping therebetween in time, space and frequency; and

, if the first and second signals that are received from the respective first and second physically distinct radioterminals, at each element, of the plurality of elements, of the antenna that is associated with the sector of the base station, relate to a Code Division Multiple Access (CDMA) protocol,

receiving a first signal from the first radioterminal, at each element, of the plurality of elements, of the antenna that is associated with the sector of the base station;

the first signal from the first radioterminal having been spread by a spreading code; and

receiving a second signal from the second radioterminal, at each element, of the plurality of elements, of the antenna that is associated with the sector of the base station;

the second signal from the second radioterminal having been spread by the same spreading code as the first signal from the first radioterminal.

2. The method according to claim 1, further comprising:

transmitting non-co-channel wireless communications from the base station to the first and second radioterminals.

3. The method according to claim 1, further comprising:

transmitting co-channel wireless communications from the base station to the first and second radioterminals.

4. The method according to claim 3, wherein transmitting co-channel wireless communications from the base station comprises:

transmitting first and second wireless communications signals from respective first and second antennas;

wherein the first and second wireless communications signals overlap in time, space and frequency; and

use the same spreading code if the signals relate to a Code Division Multiple Access (CDMA) protocol.

5. The method according to claim 1, wherein the antenna that is associated with the sector of the base station comprises at least one multiple-polarized antenna and/or a plurality of antennas that are spaced apart therebetween.

6. The method according to claim 5, wherein the at least one multiple-polarized antenna comprises a plurality of multiple-polarized antennas.

7. The method according to claim 1, wherein the base station comprises a plurality of sectors and wherein each sector of the plurality of sectors comprises an antenna that includes a plurality of antenna elements.

8. The method according to claim 7, further comprising:

receiving the first and second wireless co-channel communications using first and second antennas in respective first and second sectors of the base station.

9. The method according to claim 1, wherein the base station is a first base station and wherein receiving first and second wireless co-channel communications comprises:

receiving wireless communications using at least one antenna at the first base station and using at least one antenna at a second base station.

10. The method according to claim 1, wherein receiving first and second wireless co-channel communications further comprises:

receiving first and second wireless co-channel communications responsive to a distance between the first and second radioterminals exceeding a predetermined threshold and receiving first and second wireless communications that are not co-channel from the first and second radioterminals responsive to the distance between the two radioterminals being less than, or equal to, the predetermined threshold.

11. The method according to claim 1, wherein processing a respective plurality of signals that is provided by the plurality of elements of the antenna that is associated with the sector of the base station, to recover data, comprises:

processing the respective plurality of signals to derive first data that is associated with a first one of the first and second physically distinct radioterminals; and

using the first data to derive second data that is associated with a second one of the first and second physically distinct radioterminals.

12. A base station comprising:

a receiver that is configured to receive first and second wireless co-channel communications, at each element, of a plurality of elements, of an antenna that is associated with a sector of the base station, from respective first and second physically distinct and separate radioterminals and to process a respective plurality of signals, that is provided by the plurality of elements of the antenna that is associated with the sector of the base station, to recover data;

wherein the first and second wireless co-channel communications that are received at each element, of the plurality of elements, of the antenna that is associated with the sector of the base station, from the respective first and second physically distinct and separate radioterminals are overlapping therebetween in time, space and frequency; and

wherein if the first and second signals that are received from the respective first and second physically distinct and separate radioterminals, at each element, of the plurality of elements, of the antenna that is associated with the sector of the base station, relate to a Code Division Multiple Access (CDMA) protocol, the first signal from the first radioterminal, that is received at each element, of the plurality of elements, of the antenna that is associated with the sector of the base station comprises a first spreading code and the second signal from the second radioterminal that is received at each element, of the plurality of elements, of the antenna that is associated with the sector of the base station comprises a second spreading code that is the same as the first spreading code.

13. The base station according to claim 12, further comprising:

a transmitter that is configured to transmit wireless communications to the first and second radioterminals that are not co-channel therebetween.

14. The base station according to claim 12, further comprising:

a transmitter that is configured to transmit wireless communications to the first and second radioterminals that are co-channel therebetween.

15. The base station according to claim 14, wherein the transmitter is configured to transmit first and second wireless communications signals, from respective first and second antennas, such that the first and second wireless communications signals overlap in time, space and frequency and use the same spreading code if the first and second wireless communications signals relate to a Code Division Multiple Access (CDMA) protocol.

16. The base station according to claim 12, wherein the antenna that is associated with the sector of the base station comprises at least one multiple-polarized antenna and/or a plurality of antennas that are spaced apart therebetween.

17. The base station according to claim 16, wherein the at least one multiple-polarized antenna comprises a plurality of multiple-polarized antennas.

18. The base station according to claim 12, wherein the base station comprises a plurality of sectors and wherein each sector of the plurality of sectors comprises an antenna that includes a plurality of antenna elements.

19. The base station according to claim 18, wherein the receiver is further configured to receive the first and second wireless co-channel communications using first and second antennas in respective first and second sectors of the base station.

20. The base station according to claim 12, wherein the base station is a first base station and wherein the receiver is further configured to receive the first and second wireless co-channel communications by receiving wireless communications using at least one antenna at the first base station and using at least one antenna at a second base station.

21. The base station according to claim 12, wherein the receiver is further configured to receive first and second wireless communications, from the respective first and second physically distinct and separate radioterminals, that are co-channel therebetween, responsive to a separation distance between the first and second radioterminals exceeding a predetermined threshold and to receive first and second wireless communications, from the respective first and second physically distinct and separate radioterminals, that are not co-channel therebetween, responsive to the separation distance between the first and second radioterminals being less than, or equal to, the predetermined threshold.

22. The method according to claim 12, wherein the receiver is further configured to process the respective plurality of signals to derive first data that is associated with a first one of the first and second physically distinct and separate radioterminals and to use the first data to derive second data that is associated with a second one of the first and second physically distinct and separate radioterminals.

23. A radioterminal comprising:

a transmitter that is configured to transmit wireless communications to a base station; and

a receiver that is configured to receive first and second signals that are co-channel therebetween, to process the first and second signals to derive first data that is associated with information that is transmitted by the base station to a device other than the radioterminal and to use the first data to derive second data that is associated with information that is transmitted by the base station to the radioterminal.

24. The radioterminal according to claim 23, wherein the receiver is further configured to form first and second decision variables, to associate with each one of the first and second decision variables a measure of noise and/or interference, to select one of the first and second decision variables responsive to a noise and/or interference content thereof, to make a first decision based upon the selected decision variable and to use the first decision to make a second decision;

wherein the first and second decision variables correspond to respective first and second information that is transmitted co-channel by the base station, the first decision comprises data that is transmitted by the base station and is intended for the device other than the radioterminal and the second decision comprises data that is transmitted by the base station and is intended for the radioterminal.

25. The radioterminal according to claim 23, wherein the receiver is configured to receive the first and second signals using at least one antenna.

26. The radioterminal according to claim 25, wherein the at least one antenna comprises at least one multiple-polarized antenna and/or a plurality of antennas that are spaced apart therebetween.

27. The radioterminal according to claim 26, wherein the at least one multiple-polarized antenna comprises a plurality of multiple-polarized antennas.

28. The radioterminal according to claim 23, wherein the receiver is further configured to decode at least one of the first and second signals.

29. The radioterminal according to claim 23, wherein the first and second signals overlap in time, space and frequency and use the same spreading code if the first and second signals relate to a Code Division Multiple Access (CDMA) protocol.

30. A radioterminal comprising:

a receiver that is configured to receive wireless communications from a base station, to receive wireless communications from at least one second radioterminal and to use the wireless communications that are received from the at least one second radioterminal to process the wireless communications that are received from the base station.

31. The radioterminal according to claim 30:

wherein the receiver is configured to receive wireless communications from the base station over a forward link using a forward link alphabet; and

wherein the radioterminal further comprises a transmitter that is configured to transmit wireless communications to the base station using a return link alphabet that has fewer symbols than the forward link alphabet.

32. The radioterminal according to claim 30, wherein the receiver is further configured to process the wireless communications that are received from the base station and the wireless communications that are received from the at least one second radioterminal to derive first data that is not intended for the radioterminal and to use the first data to derive second data that is intended for the radioterminal.