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公开(公告)号:US09973365B2
公开(公告)日:2018-05-15
申请号:US15195083
申请日:2016-06-28
Applicant: Apple Inc.
Inventor: Jianglei Ma , Wen Tong , Ming Jia , Hua Xu , Peiying Zhu , Hang Zhang
CPC classification number: H04L27/263 , H04L1/0003 , H04L1/0009 , H04L5/0007 , H04L5/0023 , H04L5/0044 , H04L5/0096 , H04L27/2613 , H04L27/2628 , H04L27/2634 , H04L27/2646
Abstract: Methods and systems are provided that enable an OFDM transmitter to be used for transmitting conventional OFDM or a form of transformed OFDM. A technique is provided for transforming a coded and modulated sequence of samples prior to an IFFT that enables the transformed sequence of samples to be transmitted using conventional OFDM or transformed OFDM. The selection of a transform function for transforming the coded and modulated sequence of samples may be based on optimizing the transform function for particular operating conditions between the transmitter and receiver. In some embodiments of the invention OFDM and time transformed OFDM are multiplexed in time and/or frequency in a transmission frame. In some embodiments of the invention a pilot pattern is provided in which the pilot are sent using OFDM and data is sent using OFDM and/or transformed OFDM.
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公开(公告)号:US09929889B2
公开(公告)日:2018-03-27
申请号:US15642956
申请日:2017-07-06
Applicant: Apple Inc.
Inventor: Jianglei Ma , Ming Jia , Wen Tong , Peiying Zhu , Hang Zhang , Hua Xu , Dongsheng Yu
CPC classification number: H04L27/2611 , H04B7/06 , H04B7/08 , H04L5/0007 , H04L5/0023 , H04L25/0226 , H04L25/0232 , H04L27/2626 , H04L27/2647
Abstract: A method and apparatus for improving channel estimation within an OFDM communication system. Channel estimation in OFDM is usually performed with the aid of pilot symbols. The pilot symbols are typically spaced in time and frequency. The set of frequencies and times at which pilot symbols are inserted is referred to as a pilot pattern. In some cases, the pilot pattern is a diagonal-shaped lattice, either regular or irregular. The method first interpolates in the direction of larger coherence (time or frequency). Using these measurements, the density of pilot symbols in the direction of faster change will be increased thereby improving channel estimation without increasing overhead. As such, the results of the first interpolating step can then be used to assist the interpolation in the dimension of smaller coherence (time or frequency).
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83.
公开(公告)号:US20180069676A1
公开(公告)日:2018-03-08
申请号:US15806923
申请日:2017-11-08
Applicant: Apple Inc.
Inventor: Jianglei Ma , Ming Jia , Wen Tong , Peiying Zhu , Hang Zhang , Mo-Han Fong
CPC classification number: H04L5/0051 , H04L1/0003 , H04L1/0009 , H04L1/0618 , H04L5/0007 , H04L5/0023 , H04L5/0048 , H04L5/005 , H04L25/02 , H04L27/2602 , H04L27/2613 , H04L27/2647 , H04W52/325
Abstract: Aspects of the invention include methods and devices for inserting data and pilot symbols into Orthogonal Frequency Division Multiplexing (OFDM) frames having a time domain and a frequency domain. A method involves inserting in at least one zone of a first type a two dimensional array of data and pilot symbols in time and frequency and inserting in at least one zone of a second type a two dimensional array of data and pilot symbols in time and frequency. In some implementations the zone of the first type comprises common pilot symbols that can be detected by all receivers receiving the OFDM frame. In some implementations the zone of the second type comprises dedicated pilot symbols that are only detectable by a receiver that is aware of pre-processing used to encode the dedicated pilot symbols.
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公开(公告)号:US20180062894A1
公开(公告)日:2018-03-01
申请号:US15790678
申请日:2017-10-23
Applicant: Apple Inc.
Inventor: Jianglei Ma , Wen Tong , Ming Jia , Hua Xu , Peiying Zhu , Hang Zhang
CPC classification number: H04L27/263 , H04L1/0003 , H04L1/0009 , H04L5/0007 , H04L5/0023 , H04L5/0044 , H04L5/0096 , H04L27/2613 , H04L27/2628 , H04L27/2634 , H04L27/2646
Abstract: Methods and systems are provided that enable an OFDM transmitter to be used for transmitting conventional OFDM or a form of transformed OFDM. A technique is provided for transforming a coded and modulated sequence of samples prior to an IFFT that enables the transformed sequence of samples to be transmitted using conventional OFDM or transformed OFDM. The selection of a transform function for transforming the coded and modulated sequence of samples may be based on optimizing the transform function for particular operating conditions between the transmitter and receiver. In some embodiments of the invention OFDM and time transformed OFDM are multiplexed in time and/or frequency in a transmission frame. In some embodiments of the invention a pilot pattern is provided in which the pilot are sent using OFDM and data is sent using OFDM and/or transformed OFDM.
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公开(公告)号:US09866285B2
公开(公告)日:2018-01-09
申请号:US14865172
申请日:2015-09-25
Applicant: Apple Inc.
Inventor: Jianglei Ma , Ming Jia , Peiying Zhu , Wen Tong
CPC classification number: H04W36/08 , H04B7/022 , H04B7/04 , H04B7/0413 , H04B7/0667 , H04B7/0697 , H04J11/0069 , H04L5/0023 , H04L5/0037 , H04L5/0048 , H04L7/0008 , H04L27/2602 , H04L27/2607 , H04L27/2613 , H04L27/2627 , H04L27/2628 , H04L27/2663 , H04L27/2665 , H04L27/2672 , H04L27/2675
Abstract: A method and apparatus are provided for performing acquisition, synchronization and cell selection within an MIMO-OFDM communication system. A coarse synchronization is performed to determine a searching window. A fine synchronization is then performed by measuring correlations between subsets of signal samples, whose first signal sample lies within the searching window, and known values. The correlations are performed in the frequency domain of the received signal. In a multiple-output OFDM system, each antenna of the OFDM transmitter has a unique known value. The known value is transmitted as pairs of consecutive pilot symbols, each pair of pilot symbols being transmitted at the same subset of sub-carrier frequencies within the OFDM frame.
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公开(公告)号:US09832063B2
公开(公告)日:2017-11-28
申请号:US13680173
申请日:2012-11-19
Applicant: Apple Inc.
Inventor: Jianglei Ma , Hang Zhang , Wen Tong , Ming Jia , Peiying Zhu , Mo-Han Fong
CPC classification number: H04L27/2692 , H04B7/02 , H04B7/0452 , H04L5/0007 , H04L5/0023 , H04L5/0048 , H04L7/043 , H04L27/2613 , H04L27/265 , H04L27/2655 , H04L27/2686 , H04W24/02
Abstract: The present invention provides a preamble that is inserted into an OFDMA frame and has a common sequence for all the base stations participating in a transmission. The subscriber station performs fine synchronization using the common sequence on the common preamble, and the resulting peaks will provide the locations of candidate base stations. The base station specific search is then performed in the vicinities of those peaks by using base station specific pseudo-noise sequences. With this two stage cell search, the searching window is drastically reduced. The preamble is matched to known values by a respective receiver to decode the signals and permit multiple signals to be transferred from the transmitter to the receiver. The preamble may comprise two parts, Preamble-1 and Preamble-2, which may be used in different systems, including multioutput, multi-input (MIMO) systems.
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公开(公告)号:US20170331538A1
公开(公告)日:2017-11-16
申请号:US15665711
申请日:2017-08-01
Applicant: Apple Inc.
Inventor: Wen Tong , Hosein Nikopour , Amir Khandani , Hua Xu , Ming Jia , Peiying Zhu , Dong-sheng Yu
IPC: H04B7/04 , H04L29/06 , H04B7/06 , H04B7/0456 , H04B7/0417
CPC classification number: H04B7/0478 , H04B7/0417 , H04B7/0456 , H04B7/0634 , H04B7/0639 , H04L69/04 , H04L69/14
Abstract: A codebook C is provided in a MIMO transmitter as well as a MIMO receiver. The codebook C will include M codewords ci, where i is a unique codeword index for each codeword ci. Each codeword defines weighting factors to apply to the MIMO signals, and may correspond to channel matrices or vectors to apply to the MIMO signals prior to transmission from the respective antennas of the MIMO transmitter. The present invention creates codeword subsets Si for each codeword ci of the codebook C. Each codeword subset Si defines L codewords cj, which are selected from all the codewords ci in the codebook C. The codewords cj in a codeword subset Si are the L codewords in the entire codebook that best correlate with the corresponding codeword ci.
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88.
公开(公告)号:US20170135006A1
公开(公告)日:2017-05-11
申请号:US15355440
申请日:2016-11-18
Applicant: Apple Inc.
Inventor: Jianglei Ma , Ming Jia , Peiying Zhu , Wen Tong
IPC: H04W36/08 , H04L27/26 , H04B7/0413
CPC classification number: H04W36/08 , H04B7/022 , H04B7/04 , H04B7/0413 , H04B7/0667 , H04B7/0697 , H04J11/0069 , H04L5/0023 , H04L5/0037 , H04L5/0048 , H04L7/0008 , H04L27/2602 , H04L27/2607 , H04L27/2613 , H04L27/2627 , H04L27/2628 , H04L27/2663 , H04L27/2665 , H04L27/2672 , H04L27/2675
Abstract: A method and apparatus are provided for performing acquisition, synchronization and cell selection within an MIMO-OFDM communication system. A coarse synchronization is performed to determine a searching window. A fine synchronization is then performed by measuring correlations between subsets of signal samples, whose first signal sample lies within the searching window, and known values. The correlations are performed in the frequency domain of the received signal. In a multiple-output OFDM system, each antenna of the OFDM transmitter has a unique known value. The known value is transmitted as pairs of consecutive pilot symbols, each pair of pilot symbols being transmitted at the same subset of sub-carrier frequencies within the OFDM frame.
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公开(公告)号:US20170126301A1
公开(公告)日:2017-05-04
申请号:US15357552
申请日:2016-11-21
Applicant: APPLE INC.
Inventor: Mahmoud Taherzadehboroujeni , Hosein Nikopour , Amir Khandani , Wen Tong , Ming Jia , Peiying Zhu , Dong-Sheng Yu , Jianglei Ma
IPC: H04B7/06 , H04B7/0413
CPC classification number: H04B7/0669 , H04B7/0413 , H04B7/06 , H04B7/0697 , H04B7/0891 , H04L1/0606 , H04L1/0625 , H04L1/0643 , H04L1/0668 , H04L5/0007 , H04L5/0023 , H04L5/0028 , H04L27/2626
Abstract: Methods and devices are provided for MIMO OFDM transmitter and receivers having odd and/even numbers of transmit antennas. Various methods for pre-coding information bits before space time coding (STC) are described for enabling transmission of information bits over all antennas. Methods of decoding received signals that have been pre-coded and STC coded are also provided by embodiments of the invention. Pilot patterns for downlink and uplink transmission between a base station and one or more wireless terminals for three transmit antenna transmitters are also provided. Variable rate codes are provided that combine various fixed rate codes in a manner that results in codes whose rates are dependent on all the various fixed rate codes that are combined
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90.
公开(公告)号:US09621390B2
公开(公告)日:2017-04-11
申请号:US15143712
申请日:2016-05-02
Applicant: Apple Inc.
Inventor: Jianglei Ma , Ming Jia , Wen Tong , Peiying Zhu , Hang Zhang , Mo-Han Fong
CPC classification number: H04L5/0051 , H04L1/0003 , H04L1/0009 , H04L1/0618 , H04L5/0007 , H04L5/0023 , H04L5/0048 , H04L5/005 , H04L25/02 , H04L27/2602 , H04L27/2613 , H04L27/2647 , H04W52/325
Abstract: Aspects of the invention include methods and devices for inserting data and pilot symbols into Orthogonal Frequency Division Multiplexing (OFDM) frames having a time domain and a frequency domain. A method involves inserting in at least one zone of a first type a two dimensional array of data and pilot symbols in time and frequency and inserting in at least one zone of a second type a two dimensional array of data and pilot symbols in time and frequency. In some implementations the zone of the first type comprises common pilot symbols that can be detected by all receivers receiving the OFDM frame. In some implementations the zone of the second type comprises dedicated pilot symbols that are only detectable by a receiver that is aware of pre-processing used to encode the dedicated pilot symbols.
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