Cooperative mimo in multicell wireless networks

Abstract

A method and system for cooperative multiple-input multiple output (MIMO) transmission operations in a multicell wireless network. Under the method, antenna elements from two or more base stations are used to from an augmented MIMO antenna array that is used to transmit and receive MIMO transmissions to and from one or more terminals. The cooperative MIMO transmission scheme supports higher dimension space-time-frequency processing for increased capacity and system performance.

1 . A method comprising:
 employing antenna elements from a plurality of base stations to support cooperative multiple-input multiple-output (MIMO) transmissions in a wireless network.   
     
     
         2 . The method of  claim 1 , wherein the cooperative MIMO transmissions comprise orthogonal frequency division multiple access (OFDMA) MIMO transmissions. 
     
     
         3 . The method of  claim 1 , further comprising encoding the cooperative MIMO transmissions using space-time coding. 
     
     
         4 . The method of  claim 3 , wherein the space-time coding comprises space-time trellis coding. 
     
     
         5 . The method of  claim 3 , wherein the space-time coding comprises space-time block coding. 
     
     
         6 . The method of  claim 3 , further comprising encoding the cooperative MIMO transmissions using space-time coding with delay diversity. 
     
     
         7 . The method of  claim 1 , further comprising encoding the cooperative MIMO transmissions using space-frequency coding. 
     
     
         8 . The method of  claim 1 , further comprising encoding the cooperative MIMO transmissions using space-time-frequency coding. 
     
     
         9 . The method of  claim 1 , further comprising performing spatial multiplexing on the cooperative MIMO transmissions. 
     
     
         10 . The method of  claim 1 , wherein the cooperative MIMO transmissions include downlink transmissions from the plurality of base stations to terminals and uplink transmissions from the terminals to the plurality of base stations. 
     
     
         11 . The method of  claim 1 , further comprising performing spatial beamforming for selected MIMO transmissions. 
     
     
         12 . The method of  claim 11 , further comprising performing spatial beamforming in combination with one of space-time, space-frequency and space-time-frequency coding of the selected MIMO transmissions. 
     
     
         13 . The method of  claim 1 , further comprising transmitting a cooperative MIMO transmission to at least two terminals simultaneously. 
     
     
         14 . The method of  claim 13 , further comprising performing spatial beamforming on the cooperative MIMO transmissions such that MIMO transmissions are directed toward intended users while spatial nulling is effected toward unintended users. 
     
     
         15 . The method of  claim 1 , further comprising jointly decoding uplink MIMO transmissions received from multiple terminals. 
     
     
         16 . The method of  claim 1 , further comprising jointly decoding downlink MIMO transmissions received at multiple terminals. 
     
     
         17 . The method of  claim 1 , further comprising separately decoding uplink MIMO transmissions received from multiple terminals. 
     
     
         18 . The method of  claim 1 , further comprising jointly encoding downlink MIMO transmissions sent to multiple terminals. 
     
     
         19 . The method of  claim 18 , further comprising:
 decoding a jointly encoded downlink MIMO transmission at a terminal; and   keeping portions of data sent via jointly encoded downlink MIMO transmission intended for the terminal, while discarding other portions of data that are not intended for the terminal.   
     
     
         20 . The method of  claim 18 , further comprising separately decoding the jointly encoded downlink transmissions at each of the multiple terminals. 
     
     
         21 .- 25 . (canceled) 
     
     
         26 . The method of  claim 1 , further comprising performing cooperative MIMO transmissions to facilitate terminal handoff between wireless network cells or sectors. 
     
     
         27 .- 28 . (canceled) 
     
     
         29 . A multicell wireless network, comprising:
 a plurality of base stations, each associated with a respective cell and having a respective antenna array including at least one antenna element; and   a cooperative multiple-input multiple-output (MIMO) transmission mechanism that employs selected antenna elements from the plurality of base stations to form an augmented antenna array used to support cooperative MIMO transmissions over the wireless network.   
     
     
         30 . The multicell wireless network of  claim 29 , wherein the cooperative MIMO transmissions comprises orthogonal frequency division multiple access (OFDMA) MIMO transmissions. 
     
     
         31 . The multicell wireless network of  claim 29 , wherein the cooperative MIMO transmission mechanism encodes the cooperative MIMO transmissions using space-time coding. 
     
     
         32 . The multicell wireless network of  claim 31 , wherein the space-time coding comprises space-time trellis coding. 
     
     
         33 . The multicell wireless network of  claim 31 , wherein the space-time coding comprises space-time block coding. 
     
     
         34 . The multicell wireless network of  claim 31 , wherein the cooperative MIMO transmission mechanism encodes the cooperative MIMO transmissions using space-time coding with delay diversity. 
     
     
         35 . The multicell wireless network of  claim 29 , wherein the cooperative MIMO transmission mechanism encodes the cooperative MIMO transmissions using space-frequency coding. 
     
     
         36 . The multicell wireless network of  claim 29 , wherein the cooperative MIMO transmission mechanism encodes the cooperative MIMO transmissions using space-time-frequency coding. 
     
     
         37 . The multicell wireless network of  claim 29 , wherein the cooperative MIMO transmission mechanism performs spatial multiplexing on the cooperative MIMO transmissions. 
     
     
         38 . The multicell wireless network of  claim 29 , wherein the cooperative MIMO transmissions include downlink transmissions from the plurality of base stations to terminals and uplink transmissions from the terminals to the plurality of base stations. 
     
     
         39 . The multicell wireless network of  claim 29 , wherein the cooperative MIMO transmission mechanism performs spatial beamforming for selected MIMO transmissions. 
     
     
         40 . The multicell wireless network of  claim 39 , wherein the cooperative MIMO transmission mechanism performs spatial beamforming in combination with one of space-time, space-frequency and space-time-frequency coding of the selected MIMO transmissions. 
     
     
         41 . The multicell wireless network of  claim 29 , wherein the cooperative MIMO transmission mechanism performs transmitting a cooperative MIMO transmission to at least two terminals simultaneously. 
     
     
         42 . The multicell wireless network of  claim 41 , wherein the cooperative MIMO transmission mechanism further performs spatial beamforming on the cooperative MIMO transmissions such that MIMO transmissions are directed toward intended users while spatial nulling is effected toward unintended users. 
     
     
         43 . The multicell wireless network of  claim 29 , wherein the cooperative MIMO transmission mechanism further performs jointly decoding uplink MIMO transmissions received from multiple terminals. 
     
     
         44 . The multicell wireless network of  claim 29 , wherein the cooperative MIMO transmission mechanism further performs separately decoding uplink MIMO transmissions received from multiple terminals. 
     
     
         45 . The multicell wireless network of  claim 29 , wherein the cooperative MIMO transmission mechanism further performs jointly encoding downlink MIMO transmissions sent to multiple terminals. 
     
     
         46 .- 52 . (canceled) 
     
     
         53 . The multicell wireless network of  claim 29 , wherein the cooperative MIMO transmission mechanism performs cooperative MIMO transmissions to facilitate terminal handoff between wireless network cells or sectors. 
     
     
         54 . A wireless communication method, said method comprising:
 performing cooperative multiple-input multiple-output (MIMO) reception by jointly receiving, at antenna elements of a plurality of base stations, signals from at least one terminal; and   transmitting signals corresponding to said signals received from at least one terminal from said plurality of base stations to a first facility.   
     
     
         55 . The wireless communication method of  claim 54  further comprising
 performing, at said plurality of base stations, signal processing on said signals received from at least one terminal.   
     
     
         56 . The wireless communication method of  claim 54  further comprising:
 extracting, at said first facility, information from said signals corresponding to said signals received from at least one terminal.   
     
     
         57 . The wireless communication method of  claim 56  wherein said extracting information comprises:
 decoding said signals corresponding to said signals received from at least one terminal.   
     
     
         58 . The wireless communication method of  claim 57  wherein said decoding comprises:
 joint MIMO decoding and demodulation of said signals corresponding to said signals received from at least one terminal.   
     
     
         59 . The wireless communication method of  claim 54  wherein said first facility is centrally located with respect to said plurality of base stations. 
     
     
         60 . The wireless communication method of  claim 54  wherein said first facility is co-located with one of said plurality of base stations. 
     
     
         61 . A wireless communication method, said method comprising:
 selecting, at a terminal, at least one antenna element from a plurality of available terminal elements to transmit signals to be jointly received by a plurality of base stations;   employing said selected antenna elements to support cooperative multiple-input multiple-output (MIMO) transmissions in a wireless network.   
     
     
         62 . A wireless communications method, said method comprising:
 receiving, at a terminal, cooperative MIMO transmissions jointly sent by antenna elements at a plurality of base stations.   
     
     
         63 . The method of  claim 62 , wherein the cooperative MIMO transmissions comprise orthogonal frequency division multiple access (OFDMA) MIMO transmissions. 
     
     
         64 . The method of  claim 62  further comprising:
 decoding said cooperative MIMO transmissions at said terminal.   
     
     
         65 . The method of  claim 64  wherein said decoding comprises determining a portion of said cooperative MIMO transmissions as intended to be received by said terminal and determining a portion of said cooperative MIMO transmissions as intended for another terminal. 
     
     
         66 . The method of  claim 65  further comprising treating said portion determined as intended for another terminal as interference. 
     
     
         67 . The method of  claim 64  wherein said decoding comprises consolidating said portions of said cooperative MIMO transmissions received at said terminal with portions of said cooperative MIMO transmissions received at another terminal for joint decoding. 
     
     
         68 . A wireless communication method, said method comprising:
 receiving signals at a plurality of base stations; and   performing cooperative multiple-input multiple-output (MIMO) transmission of said signals in a wireless network by transmitting said signals over an augmented antenna array to at least one terminal, wherein said augmented array comprises selected antenna elements at said plurality of base stations.   
     
     
         69 . The method of  claim 68  further comprising encoding said signals before said signals are received at the base stations. 
     
     
         70 . The method of  claim 69  further comprising processing of said encoded signals at said plurality of base stations by adding delay signals to said encoded signals. 
     
     
         71 . The method of  claim 70  wherein said processing synchronizes the encoded signal such that said processed signals are transmitted over said selected antenna elements at the base stations in synchrony. 
     
     
         72 . The wireless communication method of  claim 68  further comprising:
 jointly encoding data intended to be received by a plurality of terminals; and   sending said jointly encoded data to said plurality of base stations.   
     
     
         73 . The wireless communication method of  claim 72  wherein said jointly encoded data is transmitted to at least one of said plurality of terminals over said selected antenna elements at the base stations by cooperative MIMO transmission.