38 results about "Quantized feedback" patented technology

Multi-user (MU-) MIMO systems with quantized feedback are designed to maximize the sum-rate via scheduling and linear precoding. To maximize throughput over the network, quantized CSIT is sent through a low-rate feedback link feedback from a plurality of users back to a base station. The base station then determines a subset of the plurality of users to transmit one or more signals to based on the received feedback and determines a preceding matrix based on the received feedback from the plurality of users wherein the precoding matrix maximizes a sum-rate throughput for the subset of the plurality of users. Additionally, based on the received feedback, the base station designs a quantization codebook. This codebook may be designed off-line and / or online. The codebook and / or precoding matrix are used to transmit signals to the users.

The present invention relates to a method for adapting the feedback rate of a quantized representation of the propagation channel in a capacity-limited feedback channel. The method comprises obtaining a reference signal from an access point; deriving a rank indication, a codebook subset selection indication and a precoding matrix index based on the obtained reference signal; sending a first feedback message conveying the rank indication and the codebook subset selection indication, and sending a second feedback message conveying the precoding matrix index, to the access point; and receiving, from the access point, data precoded by a matrix derived based on the rank indication, the codebook subset selection indication and the precoding matrix index.

Channel state information for closed-loop transmit precoding in MIMO networks is fed back from the MSs to the BSs. The feedback is quantized using codebooks shared by the MSs and BSs to reduce overhead. The codebooks can be full-rank or rank-one. The quantized feedback is applicable to any definitions of MIMO channel covariance matrix as well as MIMO channel matrix. Since these codebooks are designed for closed-loop MIMO precoded transmissions, no additional memory is needed to store the codebooks at the BS and the MS only for the quantized feedback purposes.

The present invention relates to a method for adapting the feedback rate of a quantized representation of the propagation channel in a capacity-limited feedback channel. The method comprises obtaining a reference signal from an access point; deriving a rank indication, a codebook subset selection indication and a precoding matrix index based on the obtained reference signal; sending a first feedback message conveying the rank indication and the codebook subset selection indication, and sending a second feedback message conveying the precoding matrix index, to the access point; and receiving, from the access point, data precoded by a matrix derived based on the rank indication, the codebook subset selection indication and the precoding matrix index.

Described herein is an improved apparatus for increasing the performance of a ΣΔ modulator, which may function as an ADC. In one embodiment, the ΣΔ modulator comprises a voltage to current converter, a capacitor connected between two outputs of the voltage to current converter to receive a differential input current, and a switch that can switch between connecting each output of the voltage to current converter to ground while disconnecting the other output of the voltage to current converter. In this embodiment, the ΣΔ modulator has no common mode control loop, and no reference current. This results in decreased complexity, i.e., fewer components, as well as reduced noise.

The invention provides a control system quantizer in a wireless control device and a quantization feedback control method of the control system quantizer, relating to the technical field of the quantization feedback control of the wireless control device. The quantizer comprises a system state resolver, a signal A-D converter, an embedded microprocessor and a wireless communication circuit which are connected in sequence, wherein the system state resolver is used for acquiring a system state resolving amount based on a singular value of a system matrix; the signal A-D converter is used for carrying out digital conversion on the system state resolving amount; the embedded microprocessor is used for carrying out singular value resolving on the singular value of the system matrix, giving outan information rate optimal allocation strategy, calculating quantization parameters and carrying out quantization; and the wireless communication circuit is used for carrying out source encoding andchannel coding on a quantization value, transferring the quantization value to a system state estimator for valuation and inputting an estimated value into the controller so as to realize quantizationfeedback control. According to the control system quantizer, the quantization feedback control of the system can be realized, and the minimization of required information rate can be realized on thepremise that the control performance of the system is guaranteed.

The invention discloses a hybrid pre-coding method based on quantitative feedback of a channel statistic codebook. The method specifically comprises the following steps that: firstly, a base station determines a feedback bit number of analog pre-coding and valid channel information based on the information of a signal-to-noise ratio of a transmitted signal, an antenna number, a user number and system spectrum efficiency; a user estimates channel information between the base station and the user after receiving the feedback bit number; then the user designs a quantification analog pre-coding vector of the base station for the user and feeds back the quantification analog pre-coding vector to the base station, and the base station integrates the feedback into an analog pre-coding matrix, performs analog pre-coding and transmits a training sequence of a valid channel being subjected to the analog pre-coding; the user estimate a valid channel after receiving the training sequence, and performs quantification by using a codebook based on channel statistic; and lastly, the user feeds back quantified valid channel information to the base station, and the base station performs digital pre-programming according to the fed-back channel information. The hybrid pre-coding method can be effectively applied to actual scenes; errors of channel quantification can be reduced fully; and meanwhile the capacity performance of a system is improved.

Described herein is a method and apparatus for reducing ISI in a single-bit ΣΔ modulator without reducing the dynamic range of the modulator. In one embodiment, the signal fed back to the input of the modulator is not the single-bit outputs of a quantizer as in the prior art, but rather patterns of such outputs. The patterns are selected so that each pattern has the same number of transition edges and there is thus no mismatch of transition times. In one embodiment, the patterns are created by digital logic. In another embodiment, an analog signal is added to the error signal in the feedback loop which causes the quantizer to generate the patterns. When the amplitude of the input signal exceeds a certain level, the modulator reverts to the typical operation of a prior art modulator, thus preserving the full dynamic range of the modulator.

The invention discloses a method and device for quantizing feedback of channel information and data precoding. In the above method, a channel measurement pilot signal from a base station is received; channel measurement is performed according to the channel measurement pilot signal to obtain channel information; Calculate CMatrix1 and CMatrix2 using channel information, wherein CMatrix1 and CMatrix2 are used to quantize channel information or instruct the base station to perform precoding; feed back the first indication information of CMatrix1 and / or the second indication information of CMatrix2 to the base station. According to the technical solution provided by the present invention, since the influence of polarization leakage is considered in the feedback design, there is a significant performance gain when polarization leakage actually occurs.

Provided are a method and device for reporting channel state information (CSI). The method comprises: determining, according to a first condition and a second condition, CSI to be reported, wherein the CSI to be reported comprises M types of CSI; and reporting the determined CSI to be reported. By means of the present invention, the problems in the related art that the quantized feedback of CSI is complex and have high costs are solved, thus achieving the effect of reducing the complexity and costs for the quantized feedback of CSI.

Provided in the present invention are a method and device for use in the transmission of codebook restriction signals and quantized feedback of channel information, the method for transmission of codebook restriction signals comprising: determining a codebook corresponding to different rank indicators (RIs) when channel information is fed back; dividing the codebook corresponding to different RIs into a predetermined number of groups according to the RIs, wherein the predetermined number is greater than or equal to 2; determining a codebook restriction mode corresponding to the codebook in the predetermined number of groups, wherein a first number of groups in the predetermined number of groups adopt a first codebook restriction mode, a second number of groups in the predetermined number of groups adopt a second codebook restriction mode, the first codebook restriction mode being different from the second codebook restriction mode; and transmitting codebook restriction signals according to the determined codebook restriction modes. The present invention solves the problem wherein in related technologies, the use of codebook restriction modes would result in sizable expenses, and reduces the resource expenses spent in restricting codebook.