Pilot signal transmission for an orthogonal frequency division wireless communication system
AssigneeQUALCOMM Incorporated
InventorsAlexei Gorokhov, Ayman Fawzy Naguib, Arak Sutivong, Dhananjay Ashok Gore, Tingfang Ji
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Abstract
Transmission patterns for pilot symbols transmitted from a mobile station or base station are provided. The pattern allows for improved receipt of the pilot symbols transmitted. In addition, schemes for improving the ability to multiplex pilot symbols without interference and/or biasing from different mobile stations over the same frequencies and in the same time slots.
Claims29
A wireless communication apparatus, comprising:
- at least one antenna;
- a memory that stores:
- at least one time selective pilot pattern comprising first and second clusters of time selective pilot symbols, said at least one time selective pilot pattern corresponding to a plurality of pilot symbols located in pilot symbol clusters each of which comprises a plurality of contiguous pilot symbols spanning multiple frequency tones and one symbol period, wherein the first and second clusters of time selective pilot symbols have orthogonal pilot symbols, and wherein only one pilot symbol in each of the first and second clusters of time selective pilot symbols is assigned to a maximum or minimum frequency of a hop region and none of the pilot symbols in the first and second clusters of time selective pilot symbols are assigned to a first or last symbol period of the hop region, and
- at least one frequency selective pilot pattern comprising first and second clusters of frequency selective pilot symbols, said at least one frequency selective pilot pattern corressponding to another plurality of pilot symbols located in pilot symbol clusters each of which comprises a plurality of contiguous pilot symbols spanning multiple symbol periods and one frequency subcarrier, wherein the first and second clusters of frequency selective pilot symbols have orthogonal pilot symbols , and wherein only one pilot symbol in each of the first and second clusters of frequency selective pilot symbols is assigned to the first or last symbol period of the hop region and none of the pilot symbols in the first and second clusters of frequency selective pilot symbols are assigned to the maximum or minimum frequency of the hop region;
- and
- a processor coupled with the at least one antenna and the memory, the processor configured to select one pilot pattern of the at least one time selective pilot pattern or the at least one frequency selective pilot pattern, wherein the processor is configured to place the pilot symbols of the selected pilot pattern close to the edges of the hop region according to a first order approximation of a communications channel.
A method of pilot symbol transmission in a wireless communication system, comprising:
- obtaining information regarding channel conditions of a channel from at least one sector of a base station;
- determining a selectivity of the channel based upon the information;
- choosing a pattern of pilot symbols based upon the selectivity of the channel, wherein the pattern of pilot symbols is selected from at least one time selective pilot pattern comprising first and second clusters of time selective pilot symbols, said at least one time selective pilot pattern corresponding to a plurality of pilot symbols located in pilot symbol clusters each of which comprises a plurality of contiguous pilot symbols spanning multiple frequency tones and one symbol period, wherein the first and second clusters of time selective pilot symbols have orthogonal pilot symbols, and wherein only one pilot symbol in each of the first and second clusters of time selective pilot symbols is assigned to a maximum or minimum frequency of a hop region and none of the pilot symbols in the first and second clusters of time selective pilot symbols are assigned to a first or last symbol period of the hop region, and at least one frequency selective pilot pattern comprising first and second clusters of frequency selective pilot symbols, said at least one frequency selective pilot pattern corresponding to another plurality of pilot symbols located in pilot symbol clusters each of which comprises a plurality of contiguous pilot symbols spanning multiple symbol periods and one frequency subcarrier, wherein the first and second clusters of frequency selective pilot symbols have orthogonal pilot symbols, and wherein only one pilot symbol in each of the first and second clusters of frequency selective pilot symbols is assigned to the first or last symbol period of the hop region and none of the pilot symbols in the first and second clusters of frequency selective pilot symbols are assigned to the maximum or minimum frequency of the hop region;
- and
- placing the pilot symbols of the selected pilot pattern close to the edges of the hop region according to a first order approximation of a communications channel.
A wireless communication apparatus capable of transmitting a plurality of symbols each of which is transmitted utilizing a frequency subcarrier of a group of contiguous frequency subcarriers that range from a minimum frequency to a maximum frequency and during a symbol period of a group of contiguous symbol periods that range from a first symbol period to a last symbol period, the wireless communication apparatus comprising:
- at least one antenna;
- a memory that stores a plurality of time selective pilot patterns comprising first and second clusters of time selective pilot symbols each comprising a plurality of clusters each of which comprises a plurality of contiguous pilot symbols located in pilot symbol clusters each of which comprises a plurality of contiguous pilot symbols spanning multiple frequency tones and one symbol period, wherein the first and second clusters of time selective pilot symbols have orthogonal pilot symbols, and wherein only one pilot symbol in each of the first and second clusters of time selective pilot symbols is assigned to a maximum or minimum frequency of a hop region and none of the pilot symbols in the first and second clusters of time selective pilot symbols are assigned to a first or last symbol period of the hop region, and at least one frequency selective pilot pattern comprising first and second clusters of frequency selective pilot symbols, the at least one frequency selective pilot pattern corresponding to another plurality of pilot symbols located in pilot symbol clusters each of which comprises a plurality of contiguous pilot symbols spanning multiple symbol periods and one frequency subcarrier, wherein the first and second clusters of frequency selective pilot symbols have orthogonal pilot symbols, and wherein only one pilot symbol in each of the first and second clusters of frequency selective pilot symbols is assigned to the first or last symbol period of the hop region and none of the pilot symbols in the first and second clusters of frequency selective pilot symbols are assigned to the maximum or minimum frequency of the hop region;
- and
- a processor coupled with the plurality of antennas and the memory, the processor configured to cause one pilot pattern of the plurality of pilot patterns to be transmitted from the at least one antenna during the group of contiguous symbol periods utilizing the group of contiguous frequency subcarriers, wherein the processor is configured to place the pilot pattern close to the edges of the hop region according to a first order approximation of a communications channel.
A non-transitory computer readable medium encoded with computer executable instructions for reading a data packet for transmission in a wireless network, the data packet including a preamble portion that identifies a cluster pilot pattern having a plurality of time or frequency selective clusters to be transmitted by a receiver of the data packet including at least one each of a frequency-selective pilot pattern or a time-selective pilot pattern, wherein the time selective pattern comprises first and second clusters of time selective pilot symbols and the first and second clusters of time selective pilot symbols have orthogonal pilot symbols, and wherein only one pilot symbol in each of the first and second clusters of time selective pilot symbols is assigned to a maximum or minimum frequency of a hop region and none of the pilot symbols in the first and second clusters of time selective pilot symbols are assigned to a first or last symbol period of the hop region, and wherein the frequency selective pilot pattern comprises first and second clusters of frequency selective pilot symbols and the first and second clusters of frequency selective pilot symbols have orthogonal pilot symbols, and wherein only one pilot symbol in each of the first and second clusters of frequency selective pilot symbols is assigned to the first or last symbol period of the hop region and none of the pilot symbols in the first and second clusters of frequency selective pilot symbols are assigned to the maximum or minimum frequency of the hop region, and instructions for placing the symbols of the cluster pilot pattern close to the edges of the hop region according to a first order approximation of a communications channel.
A non-transitory computer readable medium encoded with:
- computer executable instructions for pilot symbol transmission in a wireless communication system, the computer executable instructions comprising:
- instructions for obtaining information regarding channel conditions from at least a sector of a base station;
- instructions for determining, based upon the information, a selectivity of the channel;
- instructions for setting a pattern of pilot symbols having a plurality of time or frequency selective clusters based upon the selectivity of the channel, wherein the time selective pattern comprises first and second clusters of time selective pilot symbols and the first and second clusters of time selective pilot symbols have orthogonal pilot symbols, and wherein only one pilot symbol in each of the first and second clusters of time selective pilot symbols is assigned to a maximum or minimum frequency of a hop region and none of the pilot symbols in the first and second clusters of time selective pilot symbols are assigned to a first or last symbol period of the hop region, and wherein the frequency selective pilot pattern comprises first and second clusters of frequency selective pilot symbols and the first and second clusters of frequency selective pilot symbols have orthogonal pilot symbols, and wherein only one pilot symbol in each of the first and second clusters of frequency selective pilot symbols is assigned to the first or last symbol period of the hop region and none of the pilot symbols in the first and second clusters of frequency selective pilot symbols are assigned to the maximum or minimum frequency of the hop region;
- and
- instructions for placing the pattern of pilot symbols close to the edges of the hop region according to a first order approximation of a communications channel.
A processing system comprising:
- an input port;
- an output port;
- and
- processing circuitry configured to:
- obtain information from an input port regarding channel conditions from at least a sector of a base station;
- determine, based upon the information, a selectivity of the channel;
- set a pattern of clustered pilot symbols having a plurality of time or frequency selective clusters based upon the selectivity of the channel and to output a selection of the set pattern of pilot symbols through the output port, wherein the time selective pattern comprises first and second clusters of time selective pilot symbols and the first and second clusters of time selective pilot symbols have orthogonal pilot symbol , and wherein only one pilot symbol in each of the first and second clusters of time selective pilot symbols is assigned to a maximum or minimum frequency of a hop region and none of the pilot symbols in the first and second clusters of time selective pilot symbols are assigned to a first or last symbol period of the hop region, and wherein the frequency selective pilot pattern comprises first and second clusters of frequency selective pilot symbols and the first and second clusters of frequency selective pilot symbols have orthogonal pilot symbols, and wherein only one pilot symbol in each of the first and second clusters of frequency selective pilot symbols is assigned to the first or last symbol period of the hop region and none of the pilot symbols in the first and second clusters of frequency selective pilot symbols are assigned to the maximum or minimum frequency of the hop region;
- and
- place the pilot pattern of pilot symbols close to the edges of the hop region according to a first order approximation of a communications channel.
A non-transitory computer-readable medium encoded with instructions for processing a communication signal, the instructions comprising code for:
- obtaining information regarding channel conditions from at least a sector of a base station;
- determining, based upon the information, a selectivity of the channel;
- setting a pattern of pilot symbols having a plurality of time or frequency selective clusters based upon the selectivity of the channel, wherein the time selective pattern comprises first and second clusters of time selective pilot symbols and the first and second clusters of time selective pilot symbols have orthogonal pilot symbols, and wherein only one pilot symbol in each of the first and second clusters of time selective pilot symbols is assigned to a maximum or minimum frequency of a hop region and none of the pilot symbols in the first and second clusters of time selective pilot symbols are assigned to a first or last symbol period of the hop region, and wherein the frequency selective pilot pattern comprises first and second clusters of frequency selective pilot symbols and the first and second clusters of frequency selective pilot symbols have orthogonal pilot symbols, and wherein only one pilot symbol in each of the first and second clusters of frequency selective pilot symbols is assigned to the first or last symbol period of the hop region and none of the pilot symbols in the first and second clusters of frequency selective pilot symbols are assigned to the maximum or minimum frequency of the hop region;
- and
- placing the pattern of pilot symbols close to the edges of the hop region according to a first order approximation of a communications channel.
Dependencies are inferred from the claim text.