Method and Apparatus for MIMO Repeater Chains in a Wireless Communication Network

• US 20100284446A1
• Filed: 12/16/2009
• Published: 11/11/2010
• Est. Priority Date: 05/06/2009
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Andersson, Stefan, Mu, Fenghao
• Granted Patent: US 8,472,868 B2
• Time in Patent Office: Days
• US Class Current: 375/211
• CPC Class Codes: H04B 7/15521 combining by calculations packets received from different stations before transmitting the combined packets as part of network coding network coding aspects for detection or prevention of errors in the information received H04L1/0076; network traffic management with optimizing of information sizing, e.g. header compression, by using assembly and disassembly of packets H04W28/065

Abstract

In one or more embodiments taught herein, a multi-band MIMO repeater is configured to translate normal wireless mobile bands into other frequency bands in the physical layer. An advantageous, multi-hop repeater chain includes two or more such repeaters, for propagating downlink signals from a base station, and for propagating uplink signals to the base station. Each such repeater may use paralleled homodyne structure transceivers for better SNR, spectrum combiners for uplink signal aggregation, spectrum separators for downlink signal de-aggregation, water mark signal inserters for optimization, and, among other things, spectrum analyzers for frequency band selection. In at least one such embodiment, a multi-hop repeater chain is configured for MIMO operation in an LTE Advanced or other MIMO network, to deliver high data rate over larger distances—e.g., further away from cell base stations.

Claims

1. A multi-hop repeater chain for use with a wireless base station in a wireless communication network, said multi-hop repeater chain configured to de-aggregate downlink signals as they are propagated outward from the base station to mobile terminals along the multi-hop repeater chain, and to aggregate uplink signals as they are propagated inward from mobile terminals along the multi-hop repeater chain to the base station, said multi-hop repeater chain comprising:

two or more repeaters forming said multi-hop repeater chain, including at least a first repeater and a last repeater;

each said repeater comprising an uplink transceiver and a downlink transceiver that are configured to conduct repeater-to-mobile-terminal transmissions and mobile-terminal-to-repeater receptions using a base station frequency spectrum and to conduct repeater-to-repeater transmissions and receptions using a repeater frequency spectrum; and

wherein the first repeater is configured to conduct repeater-to-base-station transmissions and base-station-to-repeater receptions.

2. The multi-hop repeater chain of claim 1, wherein the uplink and downlink transceivers comprise Multiple-Input-Multiple-Output (MIMO) transceivers, supporting MIMO communications between the repeaters and between each repeater and its associated mobile terminals.

3. The multi-hop repeater chain of claim 1, wherein each repeater comprises a Layer 1 repeater.

4. The multi-hop repeater chain of claim 1, wherein, for improved signal-to-noise-ratios, the multi-hop repeater chain is configured to support concurrent multipath communications between (a) a given mobile terminal and (b) two or more repeaters in the multi-hop repeater chain, each sending to or receiving from the mobile terminal in the base station frequency spectrum, or (c) at least one repeater in the multi-hop repeater chain and the wireless base station, each sending to or receiving from the mobile terminal in the base station frequency spectrum.

5. The multi-hop repeater chain of claim 1, wherein, at one or more repeater positions in the multi-hop chain of repeaters, the multi-hop repeater chain includes two or more repeaters operating in a parallel, diversity-transmission mode for at least one of downlink signal retransmissions and uplink signal retransmissions.

6. The multi-hop repeater chain of claim 1, wherein each repeater is configured to limit its usage of the base station frequency spectrum according to base station frequency spectrum assignments of those mobile terminals directly supported by the repeater, such that each repeater operates with less power and causes less interference than if each repeater repeated over the whole base station frequency spectrum.

7. The multi-hop repeater chain of claim 6, wherein each repeater includes a repeater controller that is configured to control communication frequencies of the repeater responsive to receiving configuration messages from a master repeater in the multi-hop repeater chain, or from the base station.

8. The multi-hop repeater chain of claim 1, wherein the multi-hop repeater chain de-aggregates downlink signals as they are propagated outward along the repeater chain by, at each but the last repeater, receiving incoming downlink signals and separating them into first outgoing downlink signals, which are repeated to mobile terminals directly supported by the repeater, and second outgoing downlink signals, which are relayed to the next downstream repeater in the multi-hop repeater chain to support other mobile terminals indirectly.

9. The multi-hop repeater chain of claim 1, wherein the multi-hop repeater chain aggregates uplink signals as they are propagated inward along the repeater chain by, at each but the last repeater, receiving first incoming uplink signals transmitted from mobile terminals directly supported by the repeater, receiving second incoming uplink signals relayed from the next downstream repeater in the multi-hop repeater chain, combining the first and second incoming uplink signals into outgoing uplink signals, and repeating the outgoing uplink signals to the base station if the repeater is the first repeater, or otherwise relaying them to the next upstream repeater in the multi-hop repeater chain.

10. The multi-hop repeater of claim 1, wherein the downlink transceiver in each intermediate repeater in the multi-hop repeater chain is configured to receive incoming downlink signals relayed from the next upstream repeater, separate the incoming downlink signals into first outgoing downlink signals, which are targeted to mobile terminals directly supported by the repeater, and second outgoing downlink signals, which are targeted to mobile terminals indirectly supported by the repeater, and further configured to repeat the first outgoing downlink signals in the base station frequency spectrum, for reception by mobile terminals directly supported by the repeater, and relay the second outgoing downlink signals in the repeater frequency spectrum, for reception by the next downstream repeater in the multi-hop repeater chain.

11. The multi-hop repeater chain of claim 10, wherein the downlink transceiver includes a receiver for receiving the incoming downlink signals, a first transmitter for repeating the first outgoing downlink signals, and a second transmitter for relaying the second outgoing downlink signals, and wherein the downlink transceiver further includes a spectrum processor that includes an analog or digital baseband filter circuit that is configurable for separating the incoming downlink signals into the first and second outgoing downlink signals, according to base station frequency spectrum assignments of the mobile terminals directly supported by the repeater.

12. The multi-hop repeater of claim 1, wherein the uplink transceiver in each intermediate repeater in the multi-hop repeater chain is configured to receive first incoming uplink signals transmitted from mobile terminals directly supported by the repeater and second incoming uplink signals relayed from the next downstream repeater, and to combine the first and second incoming uplink signals into outgoing uplink signals, for relaying to the next upstream repeater in the multi-hop repeater chain.

13. The multi-hop repeater chain of claim 12, wherein the uplink transceiver includes a first receiver for receiving the first incoming uplink signals, a second receiver for receiving the second incoming uplink signals, and a transmitter for relaying the outgoing uplink signals, and wherein the uplink transceiver further includes a spectrum processor that includes an analog or digital baseband combining circuit that is configurable for combining the first and second incoming uplink signals.

14. The multi-hop repeater chain of claim 1, wherein the downlink transceiver in the first repeater includes a first transmitter for repeating first outgoing downlink signals in the base station frequency spectrum, for reception by mobile terminals directly supported by the repeater, and a second transmitter for relaying second outgoing downlink signals in the repeater frequency spectrum, for reception by the next downstream repeater in the multi-hop repeater chain, and further includes a receiver for receiving incoming downlink signals transmitted from the base station, and a spectrum processor that includes an analog or digital baseband filter circuit for separating the incoming downlink signals into said first and second outgoing downlink signals.

15. The multi-hop repeater chain of claim 1, wherein the uplink transceiver in the first repeater includes a first receiver for receiving first incoming uplink signals transmitted from mobile terminals directly supported by the repeater, a second receiver for receiving second incoming uplink signals relayed from the next downstream repeater in the multi-hop repeater chain, a spectrum processor that includes an analog or digital baseband combining circuit that is configurable for combining the first and second incoming uplink signals, to form outgoing uplink signals, and a transmitter for repeating the outgoing uplink signals to the base station in the base station frequency spectrum.

16. The multi-hop repeater chain of claim 1, wherein the first repeater is co-located with the base station.

17. The multi-hop repeater chain of claim 1, wherein each repeater includes a frequency-configurable spectrum processor that is dynamically configurable for desired aggregating and de-aggregating operations at the repeater.

18. The multi-hop repeater chain of claim 1, wherein one or more of the repeaters includes a spectrum analyzer and an associated controller, for identifying, according to interference measurements, particular frequency bands within the repeater frequency spectrum to be used by one or more of the repeaters, for repeater-to-repeater communications.

19. The multi-hop repeater chain of claim 1, wherein each repeater includes a spectrum analyzer and an associated controller, wherein the controller is configured to make interference measurements within the repeater frequency spectrum to identify one or more preferred frequency bands in the repeater frequency spectrum, for use by the repeater in relaying uplink or downlink signals.

20. The multi-hop repeater chain of claim 19, wherein each repeater further includes a repeater-to-repeater control interface, and wherein the controller in each repeater is configured either to select the preferred frequency bands and report the selected frequency bands to the other repeaters to avoid relaying conflicts between repeaters, or to report the preferred frequency bands to a master repeater and correspondingly receive frequency band assignments from the master repeater.

21. The multi-hop repeater chain of claim 1, wherein the multi-hop repeater chain of claim 1 comprises one in a plurality of like multi-hop repeater chains, each configured in a corresponding one in a plurality of neighboring cells in a wireless communication network, and wherein the multi-hop repeater chains are configured to use different patterns of base station frequency spectrum assignments for repeater-supported mobile terminals, such that the repeaters close to a cell edge in a given one of the cells communicates with mobile terminals using different portions of the base station frequency spectrum than are used by the other repeaters close to cell edges in adjacent ones of the neighboring cells.

22. The multi-hop repeater chain of claim 1, wherein each repeater includes at least one of (a) one or more variable bandwidth band pass filters or (b) one or more low-pass filters and frequency translation circuits, which are configurable via one or more control messages received by the repeater, for aggregating uplink signals and de-aggregating downlink signals at the repeater.

23. The multi-hop repeater chain of claim 1, wherein, for at least one repeater in the repeater chain, at least one of the uplink and downlink transceivers includes beam forming circuits and antenna elements, for point-to-point communications with a next repeater, or with the wireless base station.

24. The multi-hop repeater chain of claim 1, wherein the multi-hop repeater chain of claim 1 comprises one in a set of three like multi-hop repeater chains, each configured in a corresponding one of three neighboring cells in a wireless communication network, and wherein the repeater chain in a first one of the cells is configured to use low pass de-aggregation, the repeater chain in a second one of the cells is configured to use middle pass de-aggregation, and the repeater chain in a third one of the cells is configured to use high pass de-aggregation.

25. A method of repeater-based communications in a cell within a wireless communication network, said method comprising de-aggregating downlink signals as they are propagated outward along the multi-hop repeater chain from a base station in the cell, and aggregating uplink signals as they are propagated inward along the multi-hop repeater chain to the base station:

said de-aggregating comprising each but the last repeater relaying to a next repeater those downlink signals that are targeted to mobile stations indirectly supported by the repeater, and each repeater repeating those downlink signals that are targeted to mobile terminals directly supported by the repeater; and

said aggregating comprising each but the first repeater relaying to the next upstream repeater those uplink signals received from mobile stations directly supported by the repeater, each but the last repeater further relaying those uplink signals received from the next downstream repeater, and the first repeater repeating to the base station those uplink signals received from the next downstream repeater and those uplink signals received from the mobile terminals directly supported by the first repeater; and

wherein each said repeater relays in a repeater frequency spectrum and repeats in a base station frequency spectrum.

26. The method of claim 25, wherein each repeater comprises a Multiple-Input-Multiple-Output (MIMO) Orthogonal Frequency Division Multiplex (OFDM) repeater, and wherein said relaying and repeating of uplink and downlink signals are performed by the multi-hop repeater chain, and comprises relaying and repeating MIMO OFDM uplink and downlink signals.

27. The method of claim 25, further comprising operating the multi-hop repeater chain as a chain of Layer 1 repeaters.

28. The method of claim 25, further comprising, for improved signal-to-noise-ratios, providing concurrent multipath communications between (a) a given mobile terminal and (b) two or more repeaters in the multi-hop repeater chain, each sending to or receiving from the mobile terminal in the base station frequency spectrum, or (c) at least one repeater in the multi-hop repeater chain and the wireless base station, each sending to or receiving from the mobile terminal in the base station frequency spectrum.

29. The method of claim 25, wherein, at one or more repeater positions in the multi-hop chain of repeaters, the multi-hop repeater chain includes two or more repeaters and the method further comprises operating those said two or more repeaters in a parallel, diversity-transmission mode.

30. The method of claim 25, wherein said de-aggregating includes each repeater limiting its usage of the base station frequency spectrum according to base station frequency spectrum assignments of those mobile terminals directly supported by the repeater, such that each repeater consumes less power and causes less interference than if the repeater repeated over the whole base station frequency spectrum.

31. The method of claim 30, further comprising, at each repeater, receiving one or more configuration messages, for controlling communication frequencies of the repeater, and correspondingly configuring said communication frequencies of the repeater according to the configuration messages.

32. The method of claim 25, wherein said de-aggregating comprises, at each but the last repeater, receiving incoming downlink signals and separating them into first outgoing downlink signals, which are repeated in the base station frequency spectrum to mobile terminals directly supported by the repeater, and second outgoing downlink signals, which are targeted to mobile terminals indirectly supported by the repeater, and which are relayed in the repeater frequency spectrum to the next downstream repeater.

33. The method of claim 25, wherein said aggregating comprises, at each but the last repeater, receiving first incoming uplink signals transmitted from mobile terminals directly supported by the repeater, receiving second incoming uplink signals relayed from the next downstream repeater, combining the first and second incoming uplink signals into outgoing uplink signals, and repeating the outgoing uplink signals to the base station, if the repeater is the first repeater, or otherwise relaying them to the next preceding repeater.

34. The method of claim 25, wherein said de-aggregating comprises, at each intermediate repeater, receiving incoming downlink signals relayed from the next upstream repeater in the repeater frequency spectrum, separating the incoming downlink signals into first outgoing downlink signals, which are targeted to mobile terminals directly supported by the repeater, and second outgoing downlink signals, which are targeted to mobile terminals indirectly supported by the repeater, and further comprises repeating the first outgoing downlink signals in the base station frequency spectrum, for reception by mobile terminals directly supported by the repeater, and relaying the second outgoing downlink signals in the repeater frequency spectrum, for reception by the next downstream repeater.

35. The method of claim 34, further comprising receiving the incoming downlink signals in the repeater frequency spectrum using a first receiver, processing the incoming downlink signals in a baseband filter separating and translating in frequency, as needed, to obtain first and second outgoing downlink signals, repeating the first outgoing downlink signals in the base station frequency spectrum, and relaying the second outgoing downlink signals in the repeater frequency spectrum, wherein separating the incoming downlink signals into the first and second outgoing downlink signals is based on base station frequency spectrum assignments for the mobile terminals directly supported by the receiver.

36. The method of claim 25, wherein said aggregating includes, at each intermediate repeater in the multi-hop repeater chain, receiving first incoming uplink signals transmitted from mobile terminals in the base station frequency spectrum, receiving second incoming uplink signals relayed from the next succeeding repeater in the repeater frequency spectrum, combining the first and second incoming uplink signals into outgoing uplink signals, and relaying the outgoing uplink signals in the repeater frequency spectrum, to the next preceding repeater.

37. The method of claim 36, wherein combining the first and second incoming uplink signals includes converting them to baseband signals, combining them at baseband to form the outgoing uplink signals, and then shifting the outgoing uplink signals into the repeater frequency spectrum, for relaying to the next preceding repeater.

38. The method of claim 25, wherein said de-aggregating comprises, in the first repeater, receiving incoming downlink signals transmitted from the base station in the base station frequency spectrum, shifting the incoming downlink signals to baseband and separating them into first outgoing downlink signals targeted to mobile terminals directly supported by the first repeater and second outgoing downlink signals targeted to mobile terminals not directly supported by the first repeater, shifting the first outgoing downlink signals into the base station frequency spectrum and repeating them for reception by the mobile terminals directly supported by the first repeater, and shifting the second outgoing downlink signals into the repeater frequency spectrum and relaying them for reception by the next downstream repeater.

39. The method of claim 25, wherein said aggregating comprises, in the first repeater, receiving first incoming uplink signals transmitted in the base station frequency spectrum from mobile terminals directly supported by the first repeater, receiving second incoming uplink signals relayed in the repeater frequency spectrum from the next downstream repeater, shifting the first and second incoming uplink signals into baseband and combining them to form outgoing uplink signals, shifting the outgoing uplink signals into the base station frequency spectrum and repeating them to the base station.

40. The method of claim 25, further comprising dynamically configuring each repeater for desired aggregating and de-aggregating operations at the repeater.

41. The method of claim 25, further comprising measuring interference in the repeater frequency spectrum and correspondingly setting particular frequency bands in the repeater frequency spectrum, to be used by the repeaters for relaying.

42. The method of claim 25, further comprising, dynamically selecting at each repeater which particular frequency band or bands in the repeater frequency spectrum, to be used for relaying by that repeater, and advertising among the repeaters the particular frequency bands selected at each repeater.

43. The method of claim 42, further comprising receiving, at a master one of the repeaters, interference measurements from each repeater for the repeater frequency spectrum, determining repeater frequency spectrum assignments for each repeater at the master repeater according to the interference measurements, and sending the repeater frequency spectrum assignments from the master repeater to the other repeaters.

44. The method of claim 25, wherein the multi-hop repeater chain comprises one in a plurality of like multi-hop repeater chains, each configured in a corresponding one in a plurality of neighboring cells in a wireless communication network, and wherein the method further comprises using at the different multi-hop repeater chains different patterns of base station frequency spectrum assignments for repeater-supported mobile terminals, such that the last repeater at a cell edge in a given one of the cells repeats different portions of the base station frequency spectrum than the last repeater at a cell edge in an adjacent given one of the cells.

45. The method of claim 25, further comprising performing said aggregating and de-aggregating at each repeater via (a) one or more variable bandwidth band pass filters or (b) one or more low-pass filters and associated frequency translation circuits, which are configurable via one or more control messages received by the repeater, for aggregating uplink signals and de-aggregating downlink signals at the repeater.

46. The method of claim 25, further comprising performing beam forming at one or more of the repeaters, for point-to-point communications with a next repeater, or with the wireless base station.

47. The method of claim 25, further comprising performing said method in each of three neighboring cells, each cell having its own multi-hop repeater chain, including configuring the repeater chain in a first one of the cells to use low pass de-aggregation, configuring the repeater chain in a second one of the cells to use middle pass de-aggregation, and configuring the repeater chain in a third one of the cell to use high pass de-aggregation.