# US 10,320,523 B2 · Method for detecting sent sequence, receiver, and receiving device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,320,523 B2 - Document ID: US10320523B2 - Status: Granted - Kind: B2 - Application number: 15/617,759 - Filed: 2017-06-08 - Published: 2017-09-21 - Granted: 2019-06-11 - Earliest claimed: 2014-12-09 - Assignees: Huawei Technologies Co., Ltd. - Applicants: Huawei Technologies Co., Ltd. - Inventors: Bentao Wu; Bangning Mao - Web page: https://patentgrep.com/patent/US10320523B2 ## CPC - H04L 1/0054: {Maximum-likelihood or sequential decoding, e.g. Viterbi, Fano, ZJ algorithms} - H04L 25/03178: {Arrangements involving sequence estimation techniques} - H04L 27/3405: {Modifications of the signal space to increase the efficiency of transmission, e.g. reduction of the bit error rate, bandwidth, or average power} - H04L 27/38: Demodulator circuits; Receiver circuits - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A method for detecting a sent sequence, a receiver, and a receiving device in order to simplify an algorithm for detecting a sent sequence and improve detection efficiency. The method for detecting a sent sequence includes determining a maximum possible candidate value of each element in N elements of a received element sequence to obtain N maximum possible candidate values, where N is a positive integer, determining state sequences corresponding to the N maximum possible candidate values as reserved sequences to obtain N groups of reserved sequences, performing likelihood computation on the N groups of reserved sequences, and setting a reserved sequence that is in the N groups of reserved sequences and is most consistent with the element sequence as a detected sent sequence. ## Claims ### Claim 1 A method for detecting a sent sequence, applied to a receiver, comprising: determining a maximum possible candidate value of each element in N elements of a received element sequence to obtain N maximum possible candidate values, N being a positive integer, and the maximum possible candidate value of each element in the N elements of the received element sequence being determined to obtain the N maximum possible candidate values by setting i to an integer from 1 to N sequentially, and separately performing the following on an ith element: making a hard decision on the ith element to obtain a decision value of the ith element, the ith element being an element in the N elements; obtaining a first Euclidean distance between an I component of the ith element and an I component of the decision value of the ith element through computation according to the ith element and the decision value of the ith element; determining the I component of the decision value of the it element as a possible value of the I component of the ith element when the first Euclidean distance is less than or equal to a first threshold; and setting, according to a constellation corresponding to the ith element, an I component value of one or two constellation points closest to the I component of the ith element as the possible value of the I component of the ith element when the first Euclidean distance is greater than the first threshold, a plurality of constellation points being in the constellation, and each constellation point representing a possible candidate value of the ith element; determining state sequences corresponding to the N maximum possible candidate values as reserved sequences to obtain N groups of reserved sequences; performing likelihood computation on the N groups of reserved sequences; and setting a reserved sequence that is in the N groups of reserved sequences and is most consistent with the element sequence as a detected sent sequence. ### Claim 2 (depends on 1) The method of claim 1, wherein after determining the I component of the decision value of the ith element as the possible value of the I component of the ith element or after setting the I component value of one or two constellation points closest to the I component of the ith element as the possible value of the I component of the ith element, the method further comprises: obtaining a second Euclidean distance between a Q component of the ith element and a Q component of the decision value of the ith element through computation; determining the Q component of the decision value of the ith element as a possible value of the Q component of the ith element when the second Euclidean distance is less than or equal to a second threshold; and setting, according to the constellation, a Q component value of one or two constellation points closest to the Q component of the ith element as the possible value of the Q component of the ith element when the second Euclidean distance is greater than the second threshold. ### Claim 3 (depends on 2) The method of claim 2, wherein determining the maximum possible candidate value of each element in the N elements of the received element sequence to obtain the N maximum possible candidate values comprises: combining the possible value of the I component of the ith element and the possible value of the Q component of the ith element to obtain a maximum possible candidate value of the ith element; and obtaining the N maximum possible candidate values. ### Claim 4 A receiver, comprising: a transceiver configured to receive an element sequence; and a processor coupled to the transceiver and configured to: determine a maximum possible candidate value of each element in N elements of the element sequence to obtain N maximum possible candidate values by setting i to an integer from 1 to N sequentially, and separately performing the following on an ith element: make a hard decision on the ith element to obtain a decision value of the ith element, the ith element being an element in the N elements; obtain a first Euclidean distance between an I component of the ith element and an I component of the decision value of the ith element through computation according to the ith element and the decision value of the ith element; determine the I component of the decision value of the ith element as a possible value of the I component of the ith element when the first Euclidean distance is less than or equal to a first threshold; and set, according to a constellation corresponding to the ith element, an I component value of one or two constellation points closest to the I component of the ith element as the possible value of the I component of the ith element when the first Euclidean distance is greater than the first threshold, a plurality of constellation points being in the constellation, and each constellation point representing a possible candidate value of the ith element; determine state sequences corresponding to the N maximum possible candidate values as reserved sequences to obtain N groups of reserved sequences; perform likelihood computation on the N groups of reserved sequences; and set a reserved sequence that is in the N groups of reserved sequences and is most consistent with the element sequence as a detected sent sequence. ### Claim 5 (depends on 4) The receiver of claim 4, wherein the processor is further configured to: obtain a second Euclidean distance between a Q component of the ith element and a Q component of the decision value of the ith element through computation after determining the I component of the decision value of the ith element as the possible value of the I component of the ith element or setting the I component value of the one or two constellation points closest to the I component of the ith element as the possible value of the I component of the ith element; determine the Q component of the decision value of the ith element as a possible value of the Q component of the ith element when the second Euclidean distance is less than or equal to a second threshold; and set, according to the constellation, a Q component value of one or two constellation points closest to the Q component of the ith element as the possible value of the Q component of the ith element when the second Euclidean distance is greater than the second threshold. ### Claim 6 (depends on 5) The receiver of claim 5, wherein the processor is further configured to: combine the possible value of the I component of the ith element and the possible value of the Q component of the ith element to obtain a maximum possible candidate value of the ith element; and obtain the N maximum possible candidate values. ### Claim 7 A receiving device, comprising: a receiver configured to receive an element sequence; a memory coupled to the receiver and configured to store instructions; and a processor coupled to the receiver and the memory, the instructions causing the processor to be configured to: determine a maximum possible candidate value of each element in N elements of the received element sequence to obtain N maximum possible candidate values, N being a positive integer, and the maximum possible candidate value of each element in the N elements of the received element sequence being determined to obtain the N maximum possible candidate values by setting i to an integer from 1 to N sequentially, and separately performing the following on an ith element: make a hard decision on the ith element to obtain a decision value of the ith element, the ith element being an element in the N elements; obtain a first Euclidean distance between an I component of the ith element and an I component of the decision value of the ith element through computation according to the ith element and the decision value of the ith element; determine the I component of the decision value of the ith element as a possible value of the I component of the ith element when the first Euclidean distance is less than or equal to a first threshold; and set, according to a constellation corresponding to the ith element, an I component value of one or two constellation points closest to the I component of the ith element as the possible value of the I component of the ith element when the first Euclidean distance is greater than the first threshold, a plurality of constellation points being in the constellation, and each constellation point representing a possible candidate value of the ith element; determine state sequences corresponding to the N maximum possible candidate values as reserved sequences to obtain N groups of reserved sequences; perform likelihood computation on the N groups of reserved sequences; and set a reserved sequence that is in the N groups of reserved sequences and is most consistent with the element sequence as a detected sent sequence. ### Claim 8 (depends on 7) The device of claim 7, wherein the instructions further cause the processor to be configured to: obtain a second Euclidean distance between a Q component of the ith element and a Q component of the decision value of the ith element through computation after determining the I component of the decision value of the ith element as the possible value of the I component of the ith element or setting the I component value of the one or two constellation points closest to the I component of the ith element as the possible value of the I component of the ith element; determine the Q component of the decision value of the ith element as a possible value of the Q component of the ith element when the second Euclidean distance is less than or equal to a second threshold; and set, according to the constellation, a Q component value of one or two constellation points closest to the Q component of the ith element as the possible value of the Q component of the ith element when the second Euclidean distance is greater than the second threshold. ### Claim 9 A receiving device, comprising: a receiver configured to receive an element sequence; a memory coupled to the receiver and configured to store instructions, and a processor coupled to the receiver and the memory, the instructions causing the processor to be configured to: determine a maximum possible candidate value of each element in N elements of the received element sequence to obtain N maximum possible candidate values, N being a positive integer, and the maximum possible candidate value of each element in the N elements of the received element sequence being determined to obtain the N maximum possible candidate values by setting i to an integer from 1 to N sequentially, and separately performing the following on an ith element: make a hard decision on an I component and a Q component of the ith element to obtain a decision value of the I component of the ith element and a decision value of the Q component of the ith element, the ith element being an element in the N elements; obtain a first Euclidean distance between the I component of the ith element and the decision value of the I component of the ith element through computation; determine the decision value of the I component of the ith element as a possible value of the I component of the ith element when the first Euclidean distance is less than or equal to a first threshold; and set, according to a constellation corresponding to the ith element, an I component value of one or two constellation points closest to the I component of the ith element as the possible value of the I component of the ith element when the first Euclidean distance is greater than the first threshold, a plurality of constellation points being in the constellation, and each constellation point representing a possible candidate value of the ith element; determine state sequences corresponding to the N maximum possible candidate values as reserved sequences to obtain N groups of reserved sequences; perform likelihood computation on the N groups of reserved sequences; and set a reserved sequence that is in the N groups of reserved sequences and is most consistent with the element sequence as a detected sent sequence. ### Claim 10 (depends on 9) The device of claim 9, wherein the instructions further cause the processor to be configured to: obtain a second Euclidean distance between the Q component of the ith element and the decision value of the Q component of the ith element through computation after determining the decision value of the I component of the ith element as the possible value of the I component of the ith element or setting the I component value of the one or two constellation points closest to the I component of the ith element as the possible value of the I component of the ith element; determine the decision value of the Q component of the ith element as a possible value of the Q component of the ith element when the second Euclidean distance is less than a second threshold; and set, according to the constellation, a Q component value of one or two constellation points closest to the Q component of the ith element as the possible value of the Q component of the ith element when the second Euclidean distance is greater than the second threshold. ### Claim 11 (depends on 9) The device of claim 9, wherein the instructions further cause the processor to be configured to: obtain a second Euclidean distance between the Q component of the ith element and the decision value of the Q component of the ith element through computation after determining the decision value of the I component of the ith element as the possible value of the I component of the ith element or setting the I component value of the one or two constellation points closest to the I component of the ith element as the possible value of the I component of the ith element; determine the decision value of the Q component of the ith element as a possible value of the Q component of the ith element when the second Euclidean distance is equal to a second threshold; and set, according to the constellation, a Q component value of one or two constellation points closest to the Q component of the ith element as the possible value of the Q component of the ith element when the second Euclidean distance is greater than the second threshold.