Uplink multiple access method based on frozen bit patterns of polar codes
An uplink multiple access method based on the user-specific frozen bit patterns of polar codes assigned to users and relevant transmitter-receiver embodiments. The method includes encoding the information bits with a polar encoder by using the binary-valued, user-specific frozen bit patterns in frozen bit locations during encoding operation. The method further includes mapping of coded bits with symbols to be transmitted and baseband-to-RF processing performed on the symbol sequence. The generated signals of each user are transmitted by using the same time-frequency resources. The method further includes to receive the superposed signal of multiple users transmitted by means of relevant uplink radio channels. The method further includes an RF-to-baseband conversion on the received signal and detecting and decoding each user data by using an interference cancellation multiuser detector and a polar decoder that uses binary-valued pattern sequences assigned to the users in the frozen bit locations.
1. An uplink multiple access method based on user-specific frozen bit patterns of polar codes, wherein a binary-valued pattern sequence to be used in frozen bit locations is determined based on preset rules and protocols known to transmitter units and a receiver unit and wherein a length of the binary-valued pattern sequence is at most N−K, where K is an integer representing a length of an uncoded information bit sequence and N is an integer representing a length of a coded bit sequence, wherein, a transmitter signal generation comprises process steps of:
providing the binary-valued pattern sequence to be used in the frozen bit locations during a polar encoding operation;
performing a channel encoding operation to information bits using a polar encoder, wherein binary-valued, user-specific frozen bit patterns are used in frozen bit locations during the channel encoding operation;
mapping coded bits to symbols to be transmitted, wherein a generated symbol sequence is a set of complex-valued number representing a baseband signal to be transmitted;
performing a baseband-to-RF processing onto the generated symbol sequence to generate a transmitted signal;
wherein each bit of the binary-valued pattern sequence to be used in the frozen bit locations is generated according to a Bernoulli distribution, with parameter p, wherein p is a real number such that 0≤p≤1, wherein, p represents a probability of a value of a bit equal to 1 and 1-p is a probability of a value of a bit equal to 0; and storing the generated symbol sequence at the transmitter units and the receiver unit, in the step of providing the binary-valued pattern sequence to be used in the frozen bit locations during the polar encoding.
2. The uplink multiple access method according to claim 1 ; wherein the binary-valued pattern sequence to be used in the frozen bit locations is selected from a preset generated pattern sequence table according to an index information sent from the receiver unit, in the step of providing the binary-valued pattern sequence to be used in the frozen bit locations during the polar encoding operation.