Aselsan Elektronik Sanayi Ve Ticaret Anonim Sirketi

Onur Dizdar

Cagri Goken

Alptekin Yilmaz

A method is based on the user-specific frozen bit patterns of polar codes assigned to users. At the transmitter, the binary-valued user-specific frozen bit pattern sequences to be used in frozen bit locations are determined for each user, the information bits of each user are encoded using a polar encoder, and the binary-valued user-specific frozen bit patterns are used in frozen bit locations during encoding operation to improve the performance of the downlink multi-user MIMO system. Coded bits are mapped to symbols to be transmitted, and the symbols are mapped to the MIMO layers. Then, multi-antenna precoding is applied and baseband-to-RF processing is performed onto the precoded symbols to transmit the signal. The signal of all users is transmitted at the same time-frequency resources using transmit antennas. Each receiver receives the transmitted signal which is transmitted through respective downlink channels. Each user performs RF-to-baseband processing to their respective received signal.

Method for enhancing the performance of downlink multi-user MIMO systems

A hardware complexity reduction method for successive cancellation list decoders (SCL) is provided. In path pruning stages of an SCL decoding, L paths with smallest path metrics out of 2L candidate paths are chosen as surviving candidate paths as in a conventional SCL algorithm. Moreover, path indexes of L surviving candidate paths are provided in a sorted manner according to indexes at an output of a sorter module. After a path pruning, instead of L-to-1 multiplexers, (L/2+1)-to-1 multiplexers are deployed to perform copying operations of any required elements stored in dedicated registers of the L surviving candidate paths.

Hardware complexity reduction technique for successive cancellation list decoders

A method for improving performance of an uplink non-orthogonal multiple access system under imperfect received user power control. The method is based on a plurality of user-specific transmitter filters assigned to a plurality of users. At a transmitter of each user, a signal to be transmitted according to the uplink non-orthogonal multiple access (NOMA) method is filtered by a unique filter assigned to a corresponding user, and then a baseband-to-RF processing is performed onto a symbol sequence to generate a transmitted signal. Each user transmits their respective signal using a same time-frequency resource, and receiver receives a superimposed signal which is transmitted through a plurality of respective uplink channels under imperfect received power control. An RF-to-baseband conversion is applied onto a received superimposed signal. Then, a receiver signal detection module; including an interference-cancellation multi-user detector detects each user data using knowledge of a plurality of transmitter filters of each user.

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Ankara, Turkey

Onur Dizdar