Search Patents
-
Publication number: 20040141566Abstract: An apparatus for adaptively modulating/demodulating signals in a multi-input multi-output (MIMO) system having a layered time-space architecture detector and a method thereof is disclosed. The apparatus includes: a bit and power allocation information calculator for deciding an equivalent channel gain in a reverse order of Vertical-Bell laboratories Space Time (V-BLAST) based on MIMO channel information feedbacked from a receiver and determining the number of bits and transmission power to be transmitted to each transmitting antenna by using the equivalent channel gain; and adaptive modulation means for modulating signal of each layer with corresponding modulation method based on the determined number of bits and transmitting power, controlling the transmitting power and transmitting the adaptively modulated signal through each transmitting antenna.Type: ApplicationFiled: December 16, 2003Publication date: July 22, 2004Inventors: Young-Doo Kim, Inhyoung Kim, Heejung Yu, Jihoon Choi, Taehyun Jeon, Jae-Young Ahn, Yong-Hoon Lee
-
Patent number: 7453947Abstract: An apparatus for adaptively modulating/demodulating signals in a multi-input multi-output (MIMO) system having a layered time-space architecture detector and a method thereof is disclosed. The apparatus includes: a bit and power allocation information calculator for deciding an equivalent channel gain in a reverse order of Vertical-Bell laboratories Space Time (V-BLAST) based on MIMO channel information feedbacked from a receiver and determining the number of bits and transmission power to be transmitted to each transmitting antenna by using the equivalent channel gain; and adaptive modulation means for modulating signal of each layer with corresponding modulation method based on the determined number of bits and transmitting power, controlling the transmitting power and transmitting the adaptively modulated signal through each transmitting antenna.Type: GrantFiled: December 16, 2003Date of Patent: November 18, 2008Assignee: Electronics and Telecommunications Research InstituteInventors: Young-Doo Kim, Inhyoung Kim, Heejung Yu, Jihoon Choi, Taehyun Jeon, Jae-Young Ahn, Yong-Hoon Lee
-
Publication number: 20100232535Abstract: In a wireless wideband MIMO-OFDM transmission system, a method includes converting a coded bit sequence to parallel data layers, responsive to channel encoding and interleaving of an information sequence to provide the coded bit sequence; passing each data layer through a respective repetition encoder, independently interleaving respective spread data sequences from the respective repetition encoder, and amplifying the respective interleaved outputs responsive to power allocation of a respective layer of multiple layers for both I and Q channels for being combined to form complex symbols for transmission through respective multiple antennas.Type: ApplicationFiled: March 3, 2010Publication date: September 16, 2010Applicant: NEC Laboratories America, Inc.Inventors: Guosen Yue, Li Zhang, Xiaodong Wang
-
Patent number: 8254999Abstract: A quantized multi-rank beamforming scheme for multiple-antenna systems such as a multiple-input-multiple-output (MIMO) wireless downlink. User equipment (UE) estimates downlink channel and transmit power and determines rank and power allocations. A quantized beamforming matrix is then determined by the UE using successive beamforming. The UE also determines channel quality indices (CQI) which it feeds-back to the wireless downlink base station along with the index of the quantized beamforming matrix. The base station uses the CQI information to select a UE for scheduling of downlink transmission and the quantized beamforming matrix index received from the selected UE to beamform the downlink transmission to the UE. Base station overhead and is minimized while providing near-optimal performance given the constraints of a limited feed-back channel and computational complexity of the UE.Type: GrantFiled: June 8, 2011Date of Patent: August 28, 2012Assignee: NEC Laboratories America, Inc.Inventor: Mohammad A. Khojastepour
-
Publication number: 20110268215Abstract: A quantized multi-rank beamforming scheme for multiple-antenna systems such as a multiple-input-multiple-output (MIMO) wireless downlink. User equipment (UE) estimates downlink channel and transmit power and determines rank and power allocations. A quantized beamforming matrix is then determined by the UE using successive beamforming. The UE also determines channel quality indices (CQI) which it feeds-back to the wireless downlink base station along with the index of the quantized beamforming matrix. The base station uses the CQI information to select a UE for scheduling of downlink transmission and the quantized beamforming matrix index received from the selected UE to beamform the downlink transmission to the UE. Base station overhead and is minimized while providing near-optimal performance given the constraints of a limited feed-back channel and computational complexity of the UE.Type: ApplicationFiled: June 8, 2011Publication date: November 3, 2011Applicant: NEC Laboratories America, Inc.Inventor: Mohammad A. Khojastepour
-
Patent number: 8553792Abstract: This invention provides a method for jointly optimizing network coding, channel coding, and signal constellations in non-coherent wireless multiple-input multiple-output (MIMO) wireless relay networks for the case when transceivers cannot obtain any knowledge of channel state information (CSI) due to high-speed mobility of the transceivers. In the relay networks, two terminal transceivers simultaneously transmit data to an intermediate relaying transceiver, which in turn broadcasts mixed data using physical-layer network coding to both terminals. The embodiments of this invention exploit different blind space-time trellis-coded modulations (ST-TCM) for each user, whose codebook is jointly generated over a Grassmannian manifold. The method is provided by exponential mapping with affine-lattice convolution for joint optimization of channel coding, modulations, and network coding. The method is designed for fast fading channels with and without interleaving.Type: GrantFiled: January 14, 2011Date of Patent: October 8, 2013Assignee: Mitsubishi Electric Research Laboratories, Inc.Inventors: Toshiaki Koike-Akino, Philip V. Orlik
-
Patent number: RE44092Abstract: An apparatus for adaptively modulating/demodulating signals in a multi-input multi-output (MIMO) system having a layered time-space architecture detector and a method thereof is disclosed. The apparatus includes: a bit and power allocation information calculator for deciding an equivalent channel gain in a reverse order of Vertical-Bell laboratories Space Time (V-BLAST) based on MIMO channel information feedbacked from a receiver and determining the number of bits and transmission power to be transmitted to each transmitting antenna by using the equivalent channel gain; and adaptive modulation means for modulating signal of each layer with corresponding modulation method based on the determined number of bits and transmitting power, controlling the transmitting power and transmitting the adaptively modulated signal through each transmitting antenna.Type: GrantFiled: November 18, 2010Date of Patent: March 19, 2013Assignee: Electronics and Telecommunications Research InstituteInventors: Young-Doo Kim, Inhyoung Kim, Heejung Yu, Jihoon Choi, Taehyun Jeon, Jae-Young Ahn, Yong-Hoon Lee