Beijing Jiaotong University

Telefonaktiebolaget Lm Ericsson (publ)

Bo Ai

Zhangdui Zhong

Peng Liu

Jian Yu

Yu Liu

Qi Wang

Jiayi Zhang

Qingyong Li

Haiying Cao

Gang Zhu

Fanggang Wang

Vijay Venkateswaran

Ruisi He

Li'ao Gengyang

Ruifeng Chen

Jiakang Zheng

A method for realizing rate-splitting multi-access in a mobile cell-free massive MIMO system includes the following steps: splitting, by an access point, the data of each user into two parts with common message and private message, coding all the common message into one super message common message stream, coding each piece of the private message into a private message stream; coding, by the access point, the private message stream using an arbitrary linear pre-coding method, coding the super common message stream using an optimal pre-coding method, and sending the final coded super common message streams to user terminals after superimposing the final coded super common message stream on the private message streams; first decoding, by the user terminals, the super common message stream, removing the super common message stream using successive interference cancellation technology, and then decoding the private message streams.

Method for realizing splitting-rate multi-access of mobile cell-free massive MIMO system

There is provided mechanisms for mitigating passive intermodulation in a first network node, wherein said PIM is caused by radio signals transmitted from at least an adjacent network node. The method is performed by a control device. The method comprises receiving at least an uplink radio signal and down-converting the received UL radio signal to a UL baseband signal. The method applies a cyclic redundancy check, CRC, to detected information bits of the received UL baseband signal, wherein in response to determining by the CRC that the UL baseband signal is detected correctly, directly output the detected information bits. The method comprises in response to determining by the CRC that the UL baseband signal is incorrectly detected, determining a residual signal of the received UL baseband signal applying a blind signal identification scheme on the residual signal of the UL baseband signal to obtain an estimate for a modeled PIM signal. The method comprises subtracting the estimated modelled PIM signal from the received UL baseband signal as in the first step and updating the received UL baseband signal in an iterative process until CRC is detected correctly or until number of iterations exceeds a predetermined threshold.

Method for mitigating passive intermodulation and an apparatus therefor

A Kernel-power-density based method for wireless channel multipath components (MPCs) clustering. Signals get to the receiver from a transmitter via multipath propagation. MIMO channels can be modeled as double-directional, which contains the information of power, delay, direction of departure (DOD) and direction of arrival (DOA) of MPCs. The MPCs tend to appear in clusters. All the parameters of MPCs can be estimated by using high-resolution algorithms, such as MUSIC, CLEAN, SAGE, and RiMAX. Considering a data snapshot for a certain time with several clusters, which include a number of MPCs, where each MPC is represented by its power, delay, DOD and DOA. This invention adopts a novel clustering framework by using a density based method, which can better identify the local density variations of MPCs and requires no prior knowledge about clusters. It can work for the cluster oriented channel processing technology in future wireless communication field.

Method for clustering wireless channel MPCs based on a KPD doctrine

A power amplifying device with linear corrector utilizing the polynomial format to realize pre-distortion is disclosed. Its effective order estimation technique for polynomial based pre-distorter includes the following steps. Firstly, it receives the polynomial of the described pre-distorter and then, the polynomial is transformed into the matrix expression, obtaining the pre-distorter consisted of K pre-distortion functions, where K denotes the maximum order of the described polynomials. Secondly, singular value decomposition is performed for the pre-distortion matrix, obtaining singular value matrix. Thirdly, on the basis of the singular value matrix, effective rank of the pre-distortion matrix is obtained. Such effective rank of the pre-distortion matrix is determined as the effective order of the polynomial. This invention improves not only the pre-distortion performance but also lower the computational complexity of the power amplifier pre-distorter based on polynomials, which further guarantees the convergence speed and the stability of power amplifier pre-distorter based on polynomials.

Power amplifying device with linear corrector

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Beijing, China

Bo Ai