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公开(公告)号：US20160294597A1
公开(公告)日：2016-10-06
申请号：US15181687
申请日：2016-06-14
Applicant: Imagination Technologies Limited
Inventor： Mohammed El-Hajjar , Paul Murrin , Adrian J. Anderson
IPC: H04L27/26
CPC classification number: H04L27/2647 , H03M13/41 , H04L1/0054 , H04L1/06 , H04L1/0618 , H04L25/067 , H04L27/38
Abstract: Methods and apparatus for efficient demapping of constellations are described. In an embodiment, these methods may be implemented within a digital communications receiver, such as a Digital Terrestrial Television receiver. The method reduces the number of distance metric calculations which are required to calculate soft information in the demapper by locating the closest constellation point to the received symbol. This closest constellation point is identified based on a comparison of distance metrics which are calculated parallel to either the I- or Q-axis. The number of distance metric calculations may be reduced still further by identifying a local minimum constellation point for each bit in the received symbol and these constellation points are identified using a similar method to the closest constellation point. Where the system uses rotated constellations, the received symbol may be unrotated before any constellation points are identified.
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Patent Agency Ranking
公开(公告)号：US20130329838A1
公开(公告)日：2013-12-12
申请号：US13760361
申请日：2013-02-06
Applicant: IMAGINATION TECHNOLOGIES LIMITED
Inventor： Mohammed El-Hajjar , Paul Murrin , Adrian J. Anderson
IPC: H04L1/00
CPC classification number: H04L27/2647 , H03M13/41 , H04L1/0054 , H04L1/06 , H04L1/0618 , H04L25/067 , H04L27/38
Abstract: Methods and apparatus for efficient demapping of constellations are described. In an embodiment, these methods may be implemented within a digital communications receiver, such as a Digital Terrestrial Television receiver. The method reduces the number of distance metric calculations which are required to calculate soft information in the demapper by locating the closest constellation point to the received symbol. This closest constellation point is identified based on a comparison of distance metrics which are calculated parallel to either the I- or Q-axis. The number of distance metric calculations may be reduced still further by identifying a local minimum constellation point for each bit in the received symbol and these constellation points are identified using a similar method to the closest constellation point. Where the system uses rotated constellations, the received symbol may be unrotated before any constellation points are identified.
Abstract translation: 描述了有效地拆分星座的方法和装置。 在一个实施例中，这些方法可以在诸如数字地面电视接收机的数字通信接收机内实现。 该方法减少了通过将最接近的星座点定位到接收到的符号来计算解映射器中的软信息所需的距离度量计算的数量。 基于与I轴或Q轴平行计算的距离度量的比较来识别最接近的星座点。 通过识别接收到的符号中的每个位的局部最小星座点，可以进一步减少距离度量计算的数量，并且使用与最接近的星座点类似的方法来识别这些星座点。 在系统使用旋转星座的地方，在识别出任何星座点之前，接收到的符号可能未旋转。
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公开(公告)号：US11210217B2
公开(公告)日：2021-12-28
申请号：US16845303
申请日：2020-04-10
Applicant: Imagination Technologies Limited
Inventor： Paul Murrin , Adrian J. Anderson , Mohammed El-Hajjar
Abstract: Tile based interleaving and de-interleaving of row-column interleaved data is described. In one example, the de-interleaving is divided into two memory transfer stages, the first from an on-chip memory to a DRAM and the second from the DRAM to an on-chip memory. Each stage operates on part of a row-column interleaved block of data and re-orders the data items, such that the output of the second stage comprises de-interleaved data. In the first stage, data items are read from the on-chip memory according to a non-linear sequence of memory read addresses and written to the DRAM. In the second stage, data items are read from the DRAM according to bursts of linear address sequences which make efficient use of the DRAM interface and written back to on-chip memory according to a non-linear sequence of memory write addresses.
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公开(公告)号：US09819528B2
公开(公告)日：2017-11-14
申请号：US15181687
申请日：2016-06-14
Applicant: Imagination Technologies Limited
Inventor： Mohammed El-Hajjar , Paul Murrin , Adrian J. Anderson
CPC classification number: H04L27/2647 , H03M13/41 , H04L1/0054 , H04L1/06 , H04L1/0618 , H04L25/067 , H04L27/38
Abstract: Methods and apparatus for efficient demapping of constellations are described. In an embodiment, these methods may be implemented within a digital communications receiver, such as a Digital Terrestrial Television receiver. The method reduces the number of distance metric calculations which are required to calculate soft information in the demapper by locating the closest constellation point to the received symbol. This closest constellation point is identified based on a comparison of distance metrics which are calculated parallel to either the I- or Q-axis. The number of distance metric calculations may be reduced still further by identifying a local minimum constellation point for each bit in the received symbol and these constellation points are identified using a similar method to the closest constellation point. Where the system uses rotated constellations, the received symbol may be unrotated before any constellation points are identified.
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公开(公告)号：US10296456B2
公开(公告)日：2019-05-21
申请号：US13794796
申请日：2013-03-12
Applicant: Imagination Technologies Limited
Inventor： Paul Murrin , Adrian J. Anderson , Mohammed El-Hajjar
Abstract: Tile based interleaving and de-interleaving of row-column interleaved data is described. In one example, the de-interleaving is divided into two memory transfer stages, the first from an on-chip memory to a DRAM and the second from the DRAM to an on-chip memory. Each stage operates on part of a row-column interleaved block of data and re-orders the data items, such that the output of the second stage comprises de-interleaved data. In the first stage, data items are read from the on-chip memory according to a non-linear sequence of memory read addresses and written to the DRAM. In the second stage, data items are read from the DRAM according to bursts of linear address sequences which make efficient use of the DRAM interface and written back to on-chip memory according to a non-linear sequence of memory write addresses.
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公开(公告)号：US20130322425A1
公开(公告)日：2013-12-05
申请号：US13889961
申请日：2013-05-08
Applicant: IMAGINATION TECHNOLOGIES LIMITED
Inventor： Paul Murrin , Mohammed El-Hajjar
IPC: G01R29/02
CPC classification number: G01R29/02 , H04B17/345 , H04L1/20 , H04L1/206 , H04L27/2647
Abstract: Noise variance estimation and interference detection is described. In one example, a method of estimating noise variance is described in which the pilots within a received OFDM signal are divided into bands and then a noise variance estimate is calculated on a per-band basis by averaging the noise estimates for those pilots within the band. In some examples, the pilots are divided into bands in frequency and in other examples, the pilots are divided into bands in frequency and time, such that noise estimates from more than one OFDM symbol are used in calculating the per-band noise variance estimates. The noise variance estimate for a pilot is then set to the noise variance estimate for the band which contains the pilot. The noise variance estimate for a data sub-carrier can then be determined by interpolating between the values for the pilots.
Abstract translation: 描述噪声方差估计和干扰检测。 在一个示例中，描述了估计噪声方差的方法，其中接收的OFDM信号内的导频被划分成频带，然后通过对频带内的那些导频的噪声估计进行平均来计算每个频带的噪声方差估计 。 在一些示例中，导频在频率上被划分为频带，在其他示例中，导频在频率和时间上被划分成频带，使得来自多于一个OFDM符号的噪声估计被用于计算每频带噪声方差估计。 然后将导频的噪声方差估计设置为包含导频的频带的噪声方差估计。 然后可以通过在导频的值之间进行插值来确定数据子载波的噪声方差估计。
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