摘要:
Different methods of signaling between an access point and user terminals in a multiuser wireless system for performing a minimum mean square error (MMSE) precoding at the access point preceded with eigenmode selection are provided. For one embodiment of the present disclosure, a compact feedback may be utilized between a plurality of user terminals and the access point. For another embodiment of the present disclosure, a hybrid feedback may be utilized between the plurality of user terminals and the access point. For yet another embodiment of the present disclosure, a full feedback may be utilized between the plurality of user terminals and the access point.
摘要:
Different methods of signaling between an access point and user terminals in a multiuser wireless system for performing a minimum mean square error (MMSE) precoding at the access point preceded with eigenmode selection are provided. For one embodiment of the present disclosure, a compact feedback may be utilized between a plurality of user terminals and the access point. For another embodiment of the present disclosure, a hybrid feedback may be utilized between the plurality of user terminals and the access point. For yet another embodiment of the present disclosure, a full feedback may be utilized between the plurality of user terminals and the access point.
摘要:
Methods and apparatus for using code-division multiple access (CDMA) to transmit information via orthogonal frequency-division multiplexing (OFDM) to convey information from user terminals to an access point (AP) in a wireless local area network (WLAN) are provided. By using CDMA to convey information, a propagation delay between an access point (AP) and a user terminal may be determined by the AP, and timing adjustment information based on the delay may be sent to the user terminal. In this manner, subsequent uplink (UL) transmissions from multiple user terminals may be received simultaneously by the AP, despite the multiple user terminals having potentially different propagation delays.
摘要:
Methods and apparatus for using code-division multiple access (CDMA) to transmit information via orthogonal frequency-division multiplexing (OFDM) to convey information from user terminals to an access point (AP) in a wireless local area network (WLAN) are provided. By using CDMA to convey information, a propagation delay between an access point (AP) and a user terminal may be determined by the AP, and timing adjustment information based on the delay may be sent to the user terminal. In this manner, subsequent uplink (UL) transmissions from multiple user terminals may be received simultaneously by the AP, despite the multiple user terminals having potentially different propagation delays.
摘要:
A method is provided for wirelessly transmitting from a transmitter to one or more receivers within a multi-user (MU) multiple-input and multiple-output (MIMO) communication system. A number of concurrent (spatial) streams are dynamically allocated in a MU-MIMO transmission to each of a plurality of served receivers to maximize total data transmitted on each transmission. Streams are allocated according to a corresponding transmission queue length for each receiver and the number of receive antennas used by each of the served receivers. A transmission timer is started upon sending the transmission. A random backoff counter is also started upon one of either: (a) expiration of the transmission timer or (b) receipt of data at a transmission queue. A new transmission is sent upon expiration of the random backoff counter if the transmission timer has expired. Otherwise, the random backoff counter is restarted one or more times until the transmission timer has expired.
摘要:
In a first aspect, an aggregated packet (A-MPDU) includes packets (MPDUs) and EC-Blocks (Error Correction Blocks) containing error correction coding information. A transmitter uses a Fountain coding scheme (for example, Raptor or RaptorQ) to generate the error correction coding information from the MPDUs. If a receiver detects an error in a received MPDU, then the receiver uses the error correction coding information from the EC-Blocks to correct the error. In a second novel aspect, a determination is made as to whether a change in error rate is more likely due to collisions or to a low SNR. If the determination is that the change is due to collisions then the MCS index is adjusted to restore a target error rate, whereas if the determination is that the change is due to a low SNR then the number of EC-Blocks per A-MPDU is adjusted to restore the target error rate.
摘要:
The present disclosure proposes a method for preceding of a transmission signal at an access point of a multiuser system based on eigenmode selection and minimum mean square error (MMSE) processing. The most reliable eigenmodes of every multiple-input multiple-output (MIMO) channel in the system can be selected at each user terminal and corresponding eigenvalues and eigenvectors can be fed back to the access point. The linear MMSE precoding (beamforming) applied at the access point based on the selected eigenmodes may provide an improved transmission capacity performance compare to techniques from the prior art.
摘要:
Certain aspects of the present disclosure relate to a technique for communicating Channel State Information (CSI) feedback. In some aspects, the CSI feedback is communicated in a very high throughput (VHT) wireless communications system.
摘要:
Aspects of the present disclosure relate to techniques for communicating Channel State Information (CSI) feedback. According to certain aspects, a method for wireless communications is provided. The method may include determining a modulation coding scheme (MCS) or a rate for receiving channel state information. The method may further include transmitting a frame comprising a control field indicating the determined MCS or the determined rate and at least one field indicating that at least a portion of channel state information is requested.
摘要:
Methods and apparatuses are proposed for supporting one or more user-dependent channel state information (CSI) feedback rates in a downlink spatial division multiple access (SDMA) system. For certain aspects, an access point (AP) may receive a channel evolution feedback from one or more stations and send a request for CSI to the stations whose CSI values need to be updated. For certain aspects, the AP may poll the stations for updated CSI values. For certain aspects, deterministic back-off timers may be assigned to the stations indicating when to send their CSI feedback. The proposed methods may improve system performance.