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US 10,841,141 B2Granted
Pilot design for OFDM systems with four transmit antennas
AssigneeApple Inc.
InventorsJianglei Ma, Ming Jia, Wen Tong, Peiying Zhu, Claude Royer
Life of this patent
Estimating the term…
Abstract
Pilot, preamble and midamble patterns are provided that are particularly suited for four transmit antenna OFDM systems. Pilots are inserted in a scattered manner for each of the four antennas, either uncoded, space-time coded in pairs, space-time frequency coded in pairs, or space-time-frequency coded.
Claims20
A method of transmitting including using four transmit antennas, comprising:
- for each antenna of the four transmit antennas;
- generating a respective sequence of OFDM symbols, each OFDM symbol having a plurality of sub-carriers carrying data symbols or pilot symbols, wherein:
- the pilot symbols are arranged in groups, each group of pilot symbols including a pilot symbol pair for each of the four antennas, and
- a first group of pilot symbols are inserted into the OFDM symbols such that the pilot symbols for a first two of the antennas are arranged in a first pilot symbol pair, wherein the elements of the first pilot symbol pair are positioned adjacent in time on the same sub-carrier, the pilot symbols for a second two of the antennas are arranged in a second pilot symbol pair, wherein the elements of the second pilot symbol pair are positioned adjacent in time on the same sub-carrier, and the first pilot symbol pair for the first two of the antennas are non-adjacent in frequency to the second pilot symbol pair of the second two of the antennas;
- and
- transmitting the sequence of OFDM symbols.
3 more elements
A mobile station, comprising:
- four transmit antennas;
- and
- a transmitter that, for each of the four transmit antennas;
- generates a respective sequence of OFDM symbols, each OFDM symbol having a plurality of sub-carriers carrying data symbols or pilot symbols, wherein:
- the pilot symbols are arranged in groups, each group of pilot symbols including a pilot symbol pair for each of the four antennas, and
- a first group of pilot symbols are inserted into the OFDM symbols such that the pilot symbols for a first two of the antennas are arranged in a first pilot symbol pair, wherein the elements of the first pilot symbol pair are positioned adjacent in time on the same sub-carrier, the pilot symbols for a second two of the antennas are arranged in a second pilot symbol pair, wherein the elements of the second pilot symbol pair are positioned adjacent in time on the same sub-carrier, and the first pilot symbol pair for the first two of the antennas are non-adjacent in frequency to the second pilot symbol pair of the second two of the antennas;
- and
- transmits the sequence of OFDM symbols.
5 more elements
An integrated circuit, comprising;
- for each antenna of four transmit antennas;
- circuitry to generate a respective sequence of OFDM symbols, each OFDM symbol having a plurality of sub-carriers carrying data symbols or pilot symbols, wherein:
- the pilot symbols are arranged in groups, each group of pilot symbols including a pilot symbol pair for each of the four antennas, and
- a first group of pilot symbols are inserted into the OFDM symbols such that the pilot symbols for a first two of the antennas are arranged in a first pilot symbol pair, wherein the elements of the first pilot symbol pair are positioned adjacent in time on the same sub-carrier, the pilot symbols for a second two of the antennas are arranged in a second pilot symbol pair, wherein the elements of the second pilot symbol pair are positioned adjacent in time on the same sub-carrier, and the first pilot symbol pair for the first two of the antennas are non-adjacent in frequency to the second pilot symbol pair of the second two of the antennas;
- and
- circuitry to transmit the sequence of OFDM symbols.
3 more elements
Dependencies are inferred from the claim text.