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Methods and apparatus are provided for inserting data symbols and pilot symbols in an OFDM (orthogonal frequency division multiplexing) transmission resource utilizing frequency hopping patterns for the data symbols and/or the pilot symbols. Data symbols and pilot symbols are allocated for down link

Methods and apparatus are provided for inserting data symbols and pilot symbols in an OFDM (orthogonal frequency division multiplexing) transmission resource utilizing frequency hopping patterns for the data symbols and/or the pilot symbols. Data symbols and pilot symbols are allocated for down link (base station to mobile station) and up link (mobile station to bases station) transmission resources in a two-dimensional time-frequency pattern. For each antenna of a MIMO-OFDM (multiple input multiple output OFDM) communication system, pilot symbols are inserted in a scattered pattern in time-frequency and data symbols are inserted in an identical frequency-hopping pattern in time-frequency as that of other antennas.

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1. A method of inserting data symbols into Orthogonal Frequency Division Multiplexing (OFDM) frames at an OFDM transmitter having a plurality of transmitting antennas, the OFDM frames having a time domain and a frequency domain, the method comprising: for each of the plurality antennas, inserting pi

1. A method of inserting data symbols into Orthogonal Frequency Division Multiplexing (OFDM) frames at an OFDM transmitter having a plurality of transmitting antennas, the OFDM frames having a time domain and a frequency domain, the method comprising: for each of the plurality antennas, inserting pilot symbols in a respective scattered pattern in time-frequency;for each of the plurality of antennas, permuting data sub-carriers according to a frequency-hopping pattern that is identical for all of the plurality of antennas; andfor each of the plurality of antennas, mapping each of a plurality of data symbols to a selected OFDM symbol and a selected data sub-carrier. 2. The method of claim 1, wherein mapping each data symbol to at least one respective combination of a selected antenna, a selected OFDM symbol and a selected data sub-carrier comprises mapping each data symbol to at least one of an even OFDM symbol and an odd OFDM symbol defined for the selected antenna, the even OFDM symbol and the odd OFDM symbol to be transmitted consecutively by the selected antenna. 3. The method of claim 2, wherein mapping each data symbol to at least one respective combination of a selected antenna, a selected OFDM symbol and a selected data sub-carrier comprises mapping each data symbol to a respective even OFDM symbol for one antenna of the plurality of antennas, and to a respective odd OFDM symbol for another antenna of the plurality of antennas. 4. The method of claim 3, wherein mapping each data symbol to a respective even OFDM symbol for one antenna of the plurality of antennas, and to a respective odd OFDM symbol for another antenna of the plurality of antennas comprises mapping a complex conjugate of each data symbol to one of the even OFDM symbol defined for one antenna and the odd OFDM symbol defined for the other antenna. 5. The method of claim 2, wherein mapping each data symbol to at least one respective combination of a selected antenna, a selected OFDM symbol and a selected data sub-carrier comprises mapping the data symbols according to a space-time transmit diversity (STTD) coding scheme defined by the following table: Antenna 1Antenna 2EvenOddEvenOddSubcarrierSymbolSymbolSymbolSymbolSubcarrier 0s0−s24*s24s0*Subcarrier 1s1−s25*s25s1*Subcarrier 2s2−s26*s26s2*Subcarrier 3s3−s27*s27s3*Subcarrier 4s4−s28*s28s4*Subcarrier 5s5−s29*s29s5*Subcarrier 6s6−s30*s30s6*Subcarrier 7s7−s31*s31s7*Subcarrier 8s8−s32*s32s8*Subcarrier 9s9−s33*s33s9*Subcarrier 10s10−s34*s34s10*Subcarrier 11s11−s35*s35s11*Subcarrier 12s12−s36*s36s12*Subcarrier 13s13−s37*s37s13*Subcarrier 14s14−s38*S38s14*Subcarrier 15s15−s39*s39s15*Subcarrier 16s16−s40*S40s16*Subcarrier 17s17−s41*S41s17*Subcarrier 18s18−s42*s42s18*Subcarrier 19s19−s43*s43s19*Subcarrier 20s20−s44*s44s20*Subcarrier 21s21−s45*S45s21*Subcarrier 22s22−s46*S46s22*Subcarrier 23s23−s47*s47s23*. 6. The method of claim 2, wherein mapping each data symbol to at least one respective combination of a selected antenna, a selected OFDM symbol and a selected data subcarrier comprises mapping each data symbol to a one respective combination of a selected antenna, a selected OFDM symbol and a selected data subcarrier. 7. The method of claim 2, wherein mapping each data symbol to at least one respective combination of a selected antenna, a selected OFDM symbol and a selected data sub-carrier comprises mapping the data symbols according to a spatial multiplexing (SM) coding scheme defined by the following table: Antenna 1Antenna 2EvenOddEvenOddSubcarrierSymbolSymbolSymbolSymbolSubcarrier 0s0s48s1s49Subcarrier 1s2s50s3s51Subcarrier 2s4s52s5s53Subcarrier 3s6s54s7s55Subcarrier 4s8s56s9s57Subcarrier 5s10s58s11s59Subcarrier 6s12s60s13s61Subcarrier 7s14s62s15s63Subcarrier 8s16s64s17s65Subcarrier 9s18s66s19s67Subcarrier 10s20s68s21s69Subcarrier 11s22s70s23s71Subcarrier 12s24s72s25s73Subcarrier 13s26s74s27s75Subcarrier 14s28s76s29s77Subcarrier 15s30s78s31s79Subcarrier 16s32s80s33s81Subcarrier 17s34s82s35s83Subcarrier 18s36s84s37s85Subcarrier 19s38s86s39s87Subcarrier 20s40s88s41s89Subcarrier 21s42s90s43s91Subcarrier 22s44s92s45s93Subcarrier 23s46s94s47s95. 8. The method of claim 1, wherein inserting pilot symbols in a respective scattered pattern in time-frequency comprises: for a first antenna of the plurality of antennas, inserting pilot symbols in a first scattered pattern in time-frequency and inserting null symbols in a second scattered pattern in time-frequency; andfor a second antenna of the plurality of antennas, inserting pilot symbols in the second scattered pattern in time-frequency and inserting null symbols in the first scattered pattern in time-frequency. 9. The method of claim 1, wherein inserting scattered pilot symbols comprises: for a first antenna of the plurality of antennas, alternating insertion of pilot symbols and null symbols in a first diagonal arrangement in time-frequency; andfor a second antenna of the plurality of antennas, alternating insertion of pilot symbols and null symbols in a second diagonal arrangement in time-frequency such that pilot symbol locations in time-frequency for the second antenna correspond to null symbol locations in time-frequency for the first antenna, and null symbol locations in time-frequency for the second antenna correspond to pilot symbol locations in time-frequency for the first antenna. 10. The method of claim 1, wherein inserting scattered pilot symbols comprises: for a first antenna of the plurality of antennas, inserting pilot symbols in a first diagonal arrangement in time-frequency and inserting null symbols in a second diagonal arrangement in time-frequency such that the first and second arrangement are offset by a constant distance in time-frequency; andfor a second antenna of the plurality of antennas, inserting null symbols in the first diagonal arrangement in time-frequency and inserting pilot symbols in the second diagonal arrangement in time-frequency such that pilot symbol locations in time-frequency for the second antenna correspond to null symbol locations in time-frequency for the first antenna, and null symbol locations in time-frequency for the second antenna correspond to pilot symbol locations in time-frequency for the first antenna. 11. The method of claim 1, wherein: inserting pilot symbols comprises inserting the pilot symbols for each of the plurality of antennas in a respective scattered pattern in time-frequency such that pilot symbols for no two antennas occupy the same location in time-frequency; andmapping data symbols to data subcarriers comprises mapping data symbols to a set of spaced-apart subcarriers that change each symbol duration of a plurality of symbol durations. 12. The method of claim 9, wherein mapping data symbols to data subcarriers comprises mapping data symbols to a set of subcarriers that is constant over a set of consecutive symbol durations and changes for each set of multiple sets of consecutive symbol durations. 13. The method of claim 1, wherein the inserted pilot symbols and mapped data symbols do not overlap within the OFDM frame. 14. A system for inserting data symbols into Orthogonal Frequency Division Multiplexing (OFDM) frames in an OFDM transmitter having a plurality of transmitting antennas, the OFDM frames having a time domain and a frequency domain, the system comprising: at least one pilot inserter operable, for each antenna, to insert pilot symbols in a respective scattered pattern in time-frequency; andat least one encoder operable, for each of the plurality of antennas to: permute data sub-carriers according to a frequency-hopping pattern that is identical for all of the plurality of antennas; andmap each of a plurality of data symbols to a selected OFDM symbol and a selected data sub-carrier. 15. The system of claim 14, wherein: the at least one pilot inserter comprises a pilot inserter for each antenna; andthe at least one encoder comprises an encoder for each of the plurality of antennas. 16. The system of claim 14, wherein each encoder is operable to map each data symbol to at least one respective combination of a selected antenna, a selected OFDM symbol and a selected data sub-carrier by mapping each data symbol to at least one of an even OFDM symbol and an odd OFDM symbol defined for the selected antenna, the even OFDM symbol and the odd OFDM symbol to be transmitted consecutively by the selected antenna. 17. The system of claim 16, wherein each encoder is operable to map each data symbol to at least one respective combination of a selected antenna, a selected OFDM symbol and a selected data sub-carrier by mapping each data symbol to a respective even OFDM symbol for one antenna of the plurality of antennas, and to a respective odd OFDM symbol for another antenna of the plurality of antennas. 18. The system of claim 17, wherein each encoder is operable to map each data symbol to a respective even OFDM symbol for one antenna of the plurality of antennas, and to a respective odd OFDM symbol for another antenna of the plurality of antennas by mapping a complex conjugate of each data symbol to one of the even OFDM symbol defined for one antenna and the odd OFDM symbol defined for the other antenna. 19. The system of claim 16, wherein each encoder is operable to map each data symbol to at least one respective combination of a selected antenna, a selected OFDM symbol and a selected data sub-carrier by mapping the data symbols according to a space-time transmit diversity (STTD) coding scheme defined by the following table: Antenna 1Antenna 2EvenOddEvenOddSubcarrierSymbolSymbolSymbolSymbolSubcarrier 0s0−s24*s24s0*Subcarrier 1s1−s25*s25s1*Subcarrier 2s2−s26*s26s2*Subcarrier 3s3−s27*s27s3*Subcarrier 4s4−s28*s28s4*Subcarrier 5s5−s29*s29s5*Subcarrier 6s6−s30*s30s6*Subcarrier 7s7−s31*s31s7*Subcarrier 8s8−s32*s32s8*Subcarrier 9s9−s33*s33s9*Subcarrier 10s10−s34*s34s10*Subcarrier 11s11−s35*s35s11*Subcarrier 12s12−s36*s36s12*Subcarrier 13s13−s37*s37s13*Subcarrier 14s14−s38*S38s14*Subcarrier 15s15−s39*s39s15*Subcarrier 16s16−s40*S40s16*Subcarrier 17s17−s41*S41s17*Subcarrier 18s18−s42*s42s18*Subcarrier 19s19−s43*s43s19*Subcarrier 20s20−s44*s44s20*Subcarrier 21s21−s45*S45s21*Subcarrier 22s22−s46*S46s22*Subcarrier 23s23−s47*s47s23*. 20. The system of claim 16, wherein each encoder is operable to map each data symbol to at least one respective combination of a selected antenna, a selected OFDM symbol and a selected data subcarrier by mapping each data symbol to a one respective combination of a selected antenna, a selected OFDM symbol and a selected data subcarrier. 21. The system of claim 16, wherein each encoder is operable to map each data symbol to at least one respective combination of a selected antenna, a selected OFDM symbol and a selected data sub-carrier by mapping the data symbols according to a spatial multiplexing (SM) coding scheme defined by the following table: Antenna 1Antenna 2EvenOddEvenOddSubcarrierSymbolSymbolSymbolSymbolSubcarrier 0s0s48s1s49Subcarrier 1s2s50s3s51Subcarrier 2s4s52s5s53Subcarrier 3s6s54s7s55Subcarrier 4s8s56s9s57Subcarrier 5s10s58s11s59Subcarrier 6s12s60s13s61Subcarrier 7s14s62s15s63Subcarrier 8s16s64s17s65Subcarrier 9s18s66s19s67Subcarrier 10s20s68s21s69Subcarrier 11s22s70s23s71Subcarrier 12s24s72s25s73Subcarrier 13s26s74s27s75Subcarrier 14s28s76s29s77Subcarrier 15s30s78s31s79Subcarrier 16s32s80s33s81Subcarrier 17s34s82s35s83Subcarrier 18s36s84s37s85Subcarrier 19s38s86s39s87Subcarrier 20s40s88s41s89Subcarrier 21s42s90s43s91Subcarrier 22s44s92s45s93Subcarrier 23s46s94s47s95. 22. The system of claim 14, wherein the at least one pilot inserter is operable to insert pilot symbols in a respective scattered pattern in time-frequency by: for a first antenna of the plurality of antennas, inserting pilot symbols in a first scattered pattern in time-frequency and inserting null symbols in a second scattered pattern in time-frequency; andfor a second antenna of the plurality of antennas, inserting pilot symbols in the second scattered pattern in time-frequency and inserting null symbols in the first scattered pattern in time-frequency. 23. The system of claim 14, wherein the at least one pilot inserter is operable to insert scattered pilot symbols by: for a first antenna of the plurality of antennas, alternating insertion of pilot symbols and null symbols in a first diagonal arrangement in time-frequency; andfor a second antenna of the plurality of antennas, alternating insertion of pilot symbols and null symbols in a second diagonal arrangement in time-frequency such that pilot symbol locations in time-frequency for the second antenna correspond to null symbol locations in time-frequency for the first antenna, and null symbol locations in time-frequency for the second antenna correspond to pilot symbol locations in time-frequency for the first antenna. 24. The system of claim 14, wherein the pilot inserters are operable to insert scattered pilot symbols by: for a first antenna of the plurality of antennas, inserting pilot symbols in a first diagonal arrangement in time-frequency and inserting null symbols in a second diagonal arrangement in time-frequency such that the first and second arrangement are offset by a constant distance in time-frequency; andfor a second antenna of the plurality of antennas, inserting null symbols in the first diagonal arrangement in time-frequency and inserting pilot symbols in the second diagonal arrangement in time-frequency such that pilot symbol locations in time-frequency for the second antenna correspond to null symbol locations in time-frequency for the first antenna, and null symbol locations in time-frequency for the second antenna correspond to pilot symbol locations in time-frequency for the first antenna. 25. The system of claim 14, wherein: the pilot inserters are operable to insert pilot symbols by inserting the pilot symbols for each antenna in a respective scattered pattern in time-frequency such that pilot symbols for no two antennas occupy the same location in time-frequency; andeach encoder is operable to map data symbols to data subcarriers by mapping data symbols to a set of spaced-apart subcarriers that change each symbol duration of a plurality of symbol durations. 26. The system of claim 22, wherein each encoder is operable to map data symbols to data subcarriers by mapping data symbols to a set of subcarriers that is constant over a set of consecutive symbol durations and changes for each set of multiple sets of consecutive symbol durations. 27. The system of claim 14, wherein the inserted pilot symbols and mapped data symbols do not overlap within the OFDM frame.