# US 8,542,753 B1 · Detector for single-user coded signals in the presence of interference > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,542,753 B1 - Document ID: US8542753B1 - Status: Granted - Kind: B1 - Application number: 13/612,276 - Filed: 2012-09-12 - Granted: 2013-09-24 - Earliest claimed: 2008-05-29 - Assignees: Marvell International Ltd. - Applicants: Jungwon Lee; Hui-Ling Lou - Inventors: Jungwon Lee; Hui-Ling Lou - Web page: https://patentgrep.com/patent/US8542753B1 ## CPC - H04L 1/0036: {arrangements specific to the receiver} - H04L 25/03305: {Joint sequence estimation and interference removal (joint detection of several desired signals H04L25/03331)} - H04L 2025/03726: {Switching between algorithms} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Techniques are provided for detecting a coded signal in the presence of interference. In an embodiment, a primary transmitter corresponds to a desired transmitter, and one or more secondary transmitters correspond to interfering transmitters. Received symbols, which include interference and additive noise, are filtered to recover a set of original message bits. An estimate of the set of original message bits may be determined using an ordered successive interference cancellation (SIC) decoder that uses either a SIC detector or an AWGN-based detector, depending on the signal-to-interference ratio at a primary receiver. ## Claims ### Claim 1 A method of decoding symbols, the method comprising: receiving a symbol comprising a data portion, an interference portion, and a noise portion; determining a signal constellation for the symbol based on a first signal constellation associated with the data portion and a second signal constellation associated with the interference portion; decoding the interference portion based on a distance metric between the symbol and the data portion; removing the decoded interference portion from the symbol to produce a modified symbol; and decoding the data portion based on the modified symbol. ### Claim 2 (depends on 1) The method of claim 1, wherein the signal constellation for the symbol is a composition of the first signal constellation and the second signal constellation. ### Claim 3 (depends on 1) The method of claim 1, wherein the distance metric is a Euclidean distance. ### Claim 4 (depends on 1) The method of claim 1, wherein the first signal constellation and the second signal constellation correspond to the same modulation type. ### Claim 5 (depends on 1) The method of claim 1, wherein the data portion is transmitted by a primary transmitter and the interference portion is transmitted by one or more secondary transmitters. ### Claim 6 (depends on 1) The method of claim 1, further comprising decoding the data portion using a successive interference cancellation (SIC) detector. ### Claim 7 (depends on 1) The method of claim 1, wherein the first signal constellation and the second signal constellation are each non-Gaussian. ### Claim 8 (depends on 1) The method of claim 1, wherein the first signal constellation is Binary Phase Shift Keying (BPSK). ### Claim 9 (depends on 1) The method of claim 1, wherein removing the decoded interference portion from the symbol portion to produce a modified symbol comprises subtracting the decoded interference portion from the symbol portion. ### Claim 10 (depends on 5) The method of claim 5, wherein the primary transmitter and the one or more secondary transmitters transmit data asynchronously. ### Claim 11 A system comprising: receiver circuitry configured to receive a symbol comprising a data portion, an interference portion, and a noise portion; and decoding circuitry configured to: determine a signal constellation for the symbol based on a first signal constellation associated with the data portion and a second signal constellation associated with the interference portion; decode the interference portion based on a distance metric between the symbol and the data portion; remove the decoded interference portion from the symbol to produce a modified symbol; and decode the data portion based on the modified symbol. ### Claim 12 (depends on 11) The system of claim 11, wherein the signal constellation for the symbol is a composition of the first signal constellation and the second signal constellation. ### Claim 13 (depends on 11) The system of claim 11, wherein the distance metric is a Euclidean distance. ### Claim 14 (depends on 11) The system of claim 11, wherein the first signal constellation and the second signal constellation are of a common modulation type. ### Claim 15 (depends on 11) The system of claim 11, wherein the data portion is transmitted by a primary transmitter and the interference portion is transmitted by one or more secondary transmitters. ### Claim 16 (depends on 11) The system of claim 11, wherein the decoding circuitry is further configured to decode the data portion using a successive interference cancellation (SIC) detector. ### Claim 17 (depends on 11) The system of claim 11, wherein the first signal constellation and the second signal constellation are each non-Gaussian. ### Claim 18 (depends on 11) The system of claim 11, wherein the first signal constellation is Binary Phase Shift Keying (BPSK). ### Claim 19 (depends on 11) The system of claim 11, wherein the decoding circuitry is further configured to remove the decoded interference portion from the symbol portion to produce a modified symbol by subtracting the decoded interference portion from the symbol portion. ### Claim 20 (depends on 15) The system of claim 15, wherein the primary transmitter and the one or more secondary transmitters transmit data asynchronously.