Apparatus and methods for providing efficient space-time structures for preambles, pilots and data for multi-input, multi-output communications systems

Abstract

Apparatus and methods for providing efficient space-time structures for preambles, pilots and data for multi-input, multi-output (MIMO) communications systems are provided. One such embodiment includes providing a computer program that includes logic configured to provide an initial structure. The computer program further includes logic configured to verify that the rows of the initial structure are linearly independent and logic configured to apply an orthonormalization procedure to the initial structure to obtain a space-time structure. Methods are also provided for providing efficient space-time structures for preambles, pilots and data for MIMO communications systems.

We claim: 
     
       1. A computer program embodied in a computer readable medium for providing efficient space-time structures for preambles, pilots and data for multi-input, multi-output communications systems, the computer program comprising:
 logic configured to provide an initial structure;   logic configured to verify that rows of said initial structure are linearly independent;   logic configured to apply an orthonormalization procedure to said initial structure to obtain a space-time structure for a preamble or pilot in a time or frequency domain; and   logic configured to insert the space-time structure as a preamble or pilot in the time or frequency domain with one or more data symbols for transmission in the multi-input, multi-output communications system.   
     
     
       2. The computer program of  claim 1 , wherein said logic configured to provide an initial structure comprises:
 logic configured to choose a symbol alphabet to provide symbols for said initial structure; and   logic configured to choose an initial configuration of said initial structure.   
     
     
       3. The computer program of  claim 1 , further comprising:
 logic configured to confirm that symbols of said space-time structure are within a predetermined distance of symbols of said initial structure;   logic configured to construct a space-time sequence structure from a plurality of said space-time structures; and   logic configured to verify that a peak-to-average power ratio of said space-time structure is less than a predetermined value.   
     
     
       4. The computer program of  claim 3 , wherein said logic configured to confirm chat the symbols of said space-time structure are within a predetermined distance of the symbols of said initial structure comprises logic configured to apply a Euclidean distance metric to determine the distance between the symbols of said space-time structure and the symbols of said initial structure. 
     
     
       5. The computer program of  claim 1 , wherein said logic configured to verify that the rows of said initial structure are linearly independent comprises logic configured to determine rank of said initial structure. 
     
     
       6. The computer program of  claim 1 , wherein said logic configured to apply an orthonormalization procedure to said initial structure to obtain a space-time structure comprises logic configured to apply a row-wise Gram-Schmidt procedure to said initial structure to obtain a space-time structure. 
     
     
       7. A non-transitory computer readable medium having instructions stored thereon, the instructions comprising:
 instructions to produce a plurality of pilot symbols derived from at least one sequence, wherein the at least one sequence is a Frank-Zadoff or Chu sequence;   instructions to produce a plurality of data symbols;   instructions to provide a space time structure for transmission, wherein the space time structure includes a time dimension including a plurality of symbol time intervals and a space dimension including a plurality of antenna outputs; and   instructions to insert the plurality of pilot symbols and the plurality of data symbols into the space time structure for transmission in a multi-input, multi-output communications system, wherein the plurality of pilot symbols are inserted in the time and frequency domain for each antenna of the plurality of antenna outputs.   
     
     
       8. The computer readable medium of claim 7, wherein the multi-input, multi-output communications system is an orthogonal frequency division multiple access or single carrier frequency domain equalization communication system. 
     
     
       9. A method comprising:
 producing a plurality of pilot symbols derived from at least one sequence, wherein the at least one sequence is a Frank-Zadoff or Chu sequence;   producing a plurality of data symbols;   providing a space time structure for transmission, wherein the space time structure includes a time dimension including a plurality of symbol time intervals and a space dimension including a plurality of antenna outputs; and   inserting the plurality of pilot symbols and the plurality of data symbols into the space time structure for transmission in a multi-input, multi-output communications system, wherein the plurality of pilot symbols are inserted in the time and frequency domain for each antenna of the plurality of antenna outputs.   
     
     
       10. The method of claim 9, wherein the multi-input, multi-output communications system is an orthogonal frequency division multiple access or single carrier frequency domain equalization communication system. 
     
     
       11. A multi-input, multi-output communications system comprising:
 an encoder configured to:   produce a plurality of pilot symbols derived from at least one sequence, wherein the at least one sequence is a Frank-Zadoff or Chu sequence;   receive a plurality of data symbols;   provide a space time structure for transmission, wherein the space time structure includes a time dimension including a plurality of symbol time intervals and a space dimension including a plurality of antenna outputs; and   insert the plurality of pilot symbols and the plurality of data symbols into the space time structure, wherein the plurality of pilot symbols are inserted in the time and frequency domain for each antenna of the plurality of antennas; and   a plurality of modulators configured to receive an output of the encoder; and   a plurality of antennas configured to receive outputs of the plurality of modulators.   
     
     
       12. The system of claim 11, wherein the system is an orthogonal frequency division multiple access or single carrier frequency domain equalization communication system. 
     
     
       13. A multi-input, multi-output communications system comprising:
 a plurality of antennas;   a plurality of demodulators configured to receive outputs from the plurality of antennas; and   a decoder configured to receive the output of the plurality of demodulators and further configured to:   recover data from a received space time structure, wherein the space time structure includes a time dimension including a plurality of symbol time intervals and a space dimension associated with the plurality of antennas; wherein a plurality of pilot symbols and a plurality of data symbols are inserted into the space time structure; wherein the pilot symbols are inserted in the time and frequency domain for each antenna of the plurality of antennas; wherein the pilot symbols are derived from at least one sequence; and wherein the at least one sequence is a Frank-Zadoff or Chu sequence.   
     
     
       14. The system of claim 13, wherein the system is an orthogonal frequency division multiple access or single carrier frequency domain equalization communication system.