公开(公告)号：US20160119174A1

公开(公告)日：2016-04-28

申请号：US14521835

申请日：2014-10-23

Applicant: Uurmi Systems Private Limited

Inventor： Nanda Kishore Chavali ,  Syed Zeeshan Ismail

IPC: H04L27/26 ,  H04W24/08

CPC classification number: H04L27/2672 ,  H04L5/001 ,  H04L27/2659 ,  H04L27/2666

Abstract: Methods, apparatuses and systems for identifying a channel bandwidth and channel offset of an orthogonal frequency division multiplexing (OFDM) signal. The OFDM signal is received by a receiver apparatus that may be tuned to RF bandwidth of 20 MHz, 40 MHz or 80 MHz. The method utilized by the apparatus includes identifying the location of the primary channel and subsequently determining a sequence of equalized frequency domain sub-symbols of the signal field in the lower and the upper frequency band. Further, a cross-correlation between the sequence of equalized frequency domain sub-symbols is computed along with the computing energy of the sequence of equalized frequency domain sub-symbols. Finally, the cross-correlation and the computed energy are compared for identifying the channel offset and the channel bandwidth.

Abstract translation: 用于识别正交频分复用（OFDM）信号的信道带宽和信道偏移的方法，装置和系统。 OFDM信号由可被调谐到20MHz，40MHz或80MHz的RF带宽的接收机设备接收。 该装置使用的方法包括识别主信道的位置，随后确定下频段和上频带中信号域的均衡频域子符号序列。 此外，均衡频域子符号序列之间的互相关计算与均衡的频域子符号序列的计算能量一起计算。 最后，比较互相关和计算能量以识别信道偏移和信道带宽。

公开(公告)号：US20140348267A1

公开(公告)日：2014-11-27

申请号：US13899807

申请日：2013-05-22

Applicant: Uurmi Systems Private Limited

Inventor： Nanda Kishore Chavali

IPC: H04L27/26

CPC classification number: H04L27/2698 ,  H04L27/263 ,  H04L27/2634 ,  H04L27/265

Abstract: A low latency transmitter and receiver for an OFDM system are disclosed. The low latency transmitter includes an FFT module and a baseband modulator. The FFT module computes IDFT of PSK constellation data symbols or QAM constellation data symbols. The baseband modulator performs complex modulation of the IDFT samples by multiplying these samples with 1 and −1 alternatively in time domain. The low latency receiver includes a baseband demodulator and another FFT module. The baseband demodulator performs complex demodulation of the received samples of OFDM symbols by multiplying the samples of OFDM symbols with 1 and −1 alternatively in time domain thereby obtaining baseband demodulated symbols. The FFT module of the receiver computes DFT of samples of the baseband demodulated symbols to obtain samples of the OFDM demodulated symbols.

Abstract translation: 公开了一种用于OFDM系统的低延迟发射机和接收机。 低延迟发射机包括FFT模块和基带调制器。 FFT模块计算PSK星座数据符号或QAM星座数据符号的IDFT。 基带调制器通过在时域中将这些样本与1和-1相乘来进行IDFT采样的复数调制。 低延迟接收器包括基带解调器和另一个FFT模块。 基带解调器通过在时域中交替地将OFDM符号的样本乘以1和-1来进行OFDM符号的接收样本的复杂解调，从而获得基带解调符号。 接收机的FFT模块计算基带解调符号的样本的DFT，以获得OFDM解调符号的采样。

公开(公告)号：US09203679B2

公开(公告)日：2015-12-01

申请号：US13899807

申请日：2013-05-22

Applicant: Uurmi Systems Private Limited

Inventor： Nanda Kishore Chavali

IPC: H04K1/10 ,  H04L27/28 ,  H04L27/26

CPC classification number: H04L27/2698 ,  H04L27/263 ,  H04L27/2634 ,  H04L27/265

Abstract: A low latency transmitter and receiver for an OFDM system are disclosed. The low latency transmitter includes an FFT module and a baseband modulator. The FFT module computes IDFT of PSK constellation data symbols or QAM constellation data symbols. The baseband modulator performs complex modulation of the IDFT samples by multiplying these samples with 1 and −1 alternatively in time domain. The low latency receiver includes a baseband demodulator and another FFT module. The baseband demodulator performs complex demodulation of the received samples of OFDM symbols by multiplying the samples of OFDM symbols with 1 and −1 alternatively in time domain thereby obtaining baseband demodulated symbols. The FFT module of the receiver computes DFT of samples of the baseband demodulated symbols to obtain samples of the OFDM demodulated symbols.

Abstract translation: 公开了一种用于OFDM系统的低延迟发射机和接收机。 低延迟发射机包括FFT模块和基带调制器。 FFT模块计算PSK星座数据符号或QAM星座数据符号的IDFT。 基带调制器通过在时域中将这些样本与1和-1相乘来进行IDFT采样的复数调制。 低延迟接收器包括基带解调器和另一个FFT模块。 基带解调器通过在时域中交替地将OFDM符号的样本乘以1和-1来进行OFDM符号的接收样本的复杂解调，从而获得基带解调符号。 接收机的FFT模块计算基带解调符号的样本的DFT，以获得OFDM解调符号的采样。

公开(公告)号：US08982979B2

公开(公告)日：2015-03-17

申请号：US13856227

申请日：2013-04-03

Applicant: Uurmi Systems Private Limited

Inventor： Nanda Kishore Chavali ,  Kranti Kumar Balaga

IPC: H04B7/02 ,  H04L1/02 ,  H04B7/04

CPC classification number: H04B7/0413 ,  H04B7/0854

Abstract: Method and system for decomposing a complex channel matrix at MIMO receiver is disclosed. The method comprises determining a real channel matrix from the complex channel matrix, wherein the number of rows and columns of the real channel matrix depends on a number of transmitting chains and a number of receiving chains. Thereafter, the below mentioned steps repeated predetermined number of times: A pre-Householder vector is determined based on the real channel matrix. A Householder vector is determined based on the pre-Householder vector. Thereafter a Householder matrix is determined based on the Householder vector and a transpose of the Householder vector without performing division operation. Finally, an orthogonal matrix and an upper triangular matrix are determined based on the Householder matrix, wherein the upper triangular matrix comprises a predetermined number of zeros in an upper triangle.

Abstract translation: 公开了一种在MIMO接收机上分解复杂信道矩阵的方法和系统。 该方法包括从复信道矩阵确定真实信道矩阵，其中，实数信道矩阵的行数和列数取决于多个发送链和多个接收链。 此后，下面提到的步骤重复预定次数：基于实数通道矩阵确定一个前农民矢量。 一个户主向量是根据前议员向量确定的。 此后，根据“房主”矢量和房主向量的转置，而不进行分工操作，确定了一个房屋矩阵。 最后，基于Householder矩阵确定正交矩阵和上三角矩阵，其中上三角矩阵包括上三角形中的预定数量的零。

公开(公告)号：US09537702B2

公开(公告)日：2017-01-03

申请号：US14521835

申请日：2014-10-23

Applicant: Uurmi Systems Private Limited

Inventor： Nanda Kishore Chavali ,  Syed Zeeshan Ismail

IPC: H04L27/26 ,  H04L5/00

CPC classification number: H04L27/2672 ,  H04L5/001 ,  H04L27/2659 ,  H04L27/2666

Abstract: Methods, apparatuses and systems for identifying a channel bandwidth and channel offset of an orthogonal frequency division multiplexing (OFDM) signal. The OFDM signal is received by a receiver apparatus that may be tuned to RF bandwidth of 20 MHz, 40 MHz or 80 MHz. The method utilized by the apparatus includes identifying the location of the primary channel and subsequently determining a sequence of equalized frequency domain sub-symbols of the signal field in the lower and the upper frequency band. Further, a cross-correlation between the sequence of equalized frequency domain sub-symbols is computed along with the computing energy of the sequence of equalized frequency domain sub-symbols. Finally, the cross-correlation and the computed energy are compared for identifying the channel offset and the channel bandwidth.

Abstract translation: 用于识别正交频分复用（OFDM）信号的信道带宽和信道偏移的方法，装置和系统。 OFDM信号由可被调谐到20MHz，40MHz或80MHz的RF带宽的接收机设备接收。 该装置使用的方法包括识别主信道的位置，随后确定下频段和上频带中信号域的均衡频域子符号序列。 此外，均衡频域子符号序列之间的互相关计算与均衡的频域子符号序列的计算能量一起计算。 最后，比较互相关和计算能量以识别信道偏移和信道带宽。

公开(公告)号：US20140301504A1

公开(公告)日：2014-10-09

申请号：US13856227

申请日：2013-04-03

Applicant: UURMI SYSTEMS PRIVATE LIMITED

Inventor： Nanda Kishore Chavali ,  Kranti Kumar Balaga

IPC: H04B7/04

CPC classification number: H04B7/0413 ,  H04B7/0854

Abstract: Method and system for decomposing a complex channel matrix at MIMO receiver is disclosed. The method comprises determining a real channel matrix from the complex channel matrix, wherein the number of rows and columns of the real channel matrix depends on a number of transmitting chains and a number of receiving chains. Thereafter, the below mentioned steps repeated predetermined number of times: A pre-Householder vector is determined based on the real channel matrix. A Householder vector is determined based on the pre-Householder vector. Thereafter a Householder matrix is determined based on the Householder vector and a transpose of the Householder vector without performing division operation. Finally, an orthogonal matrix and an upper triangular matrix are determined based on the Householder matrix, wherein the upper triangular matrix comprises a predetermined number of zeros in an upper triangle.

Abstract translation: 公开了一种在MIMO接收机上分解复杂信道矩阵的方法和系统。 该方法包括从复信道矩阵确定真实信道矩阵，其中，实数信道矩阵的行数和列数取决于多个发送链和多个接收链。 此后，下面提到的步骤重复预定次数：基于实数通道矩阵确定一个前农民矢量。 一个户主向量是根据前议员向量确定的。 此后，根据“房主”矢量和房主向量的转置，而不进行分工操作，确定了一个房屋矩阵。 最后，基于Householder矩阵确定正交矩阵和上三角矩阵，其中上三角矩阵包括上三角形中的预定数量的零。