# US 2014/0155010 A1 · Successive interference cancellation (sic) ordering algorithms for improved multiple-input multiple-output (mimo) performance > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0155010 A1 - Document ID: US20140155010A1 - Status: Published application - Kind: A1 - Application number: 13/705,878 - Filed: 2012-12-05 - Published: 2014-06-05 - Earliest claimed: 2012-12-05 - Assignees: QUALCOMM Incorporated - Applicants: Qualcomm Incorporated - Inventors: Supratik Bhattacharjee; Brian Clarke Banister - Web page: https://patentgrep.com/patent/US20140155010A1 ## CPC - H04B 1/1027: {assessing signal quality or detecting noise/interference for the received signal} - H04J 11/0043: {by grouping or ordering the users} - H04L 25/03891: {Spatial equalizers (MIMO diversity systems H04B7/0413)} - H04L 2025/03426: {transmission using multiple-input and multiple-output channels} - H04B: TRANSMISSION - H04J: MULTIPLEX COMMUNICATION (transmission in general H04B; peculiar to transmission of digital information H04L5/00; systems for the simultaneous or sequential transmission of more than one television signal H04N7/08; in exchanges H04Q11/00; stereophonic systems H04S) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Certain aspects of the present disclosure provide ordering techniques for a Successive Interference Cancellation (SIC) receiver which may be used to robustly choose a correct stream for first decode under varying data rates, SNR and mobile propagation conditions in Multiple Input Multiple Output (MIMO) systems. The SIC ordering techniques discussed in the disclosure include SNR and/or Rate based information theoretic approach. For example, the SIC receiver may evaluate an SNR based or RATE-based information theoretic metric for the MIMO streams and choose one stream with a higher value of the metric for decoding first. A speculative single code block based approach is may also be used for selecting a stream for first decode, by leveraging the presence of per code block Cyclic Redundancy Check (CRC) and the lack of time diversity in LTE systems. ## Claims ### Claim 1 A method for wireless communication by a receiver, comprising: receiving at least two streams of data; selecting at least one of the received streams to decode first, from a comparison of a metric corresponding to at least two of the streams, the metric based on a gap between a measured value of a parameter and an allocated value of the parameter; and performing interference cancelation using results of decoding the selected at least one stream to decode at least one non-selected stream. ### Claim 2 (depends on 1) The method of claim 1, further comprising: determining the metric for a stream of data using a measured value of the parameter and an allocated value of the parameter for the stream. ### Claim 3 (depends on 2) The method of claim 2, wherein the metric is averaged over multiple transmissions for the stream. ### Claim 4 (depends on 1) The method of claim 1, wherein selecting one of the received streams to decode first comprises: selecting a stream corresponding to the largest metric value. ### Claim 5 (depends on 1) The method of claim 1, wherein the parameter comprises signal-to-noise ratio or data rate. ### Claim 6 (depends on 5) The method of claim 5, wherein the allocated signal-to-noise ratio comprises an expected signal-to-noise ratio based on an allocated data rate. ### Claim 7 (depends on 5) The method of claim 5, wherein the allocated data rate for a stream is determined using a number of symbols used for each transmission of the stream and a transport block size. ### Claim 8 A method for wireless communication, comprising: receiving at least first and second streams of data; attempting to decode at least a first code block of the first stream; and if the first code block of the first stream decodes successfully, selecting the first stream to decode first and performing interference cancelation using results of decoding the first stream to decode the second stream. ### Claim 9 (depends on 8) The method of claim 8, wherein each of the first and the second streams comprises code blocks received within one Long Term Evolution (LTE) subframe. ### Claim 10 (depends on 8) The method of claim 8, wherein attempting to decode the first code block comprises performing a Cyclic Redundancy Check (CRC) for the first code block. ### Claim 11 An apparatus for wireless communication, comprising: means for receiving at least two streams of data; means for selecting at least one of the received streams to decode first, from a comparison of a metric corresponding to at least two of the streams, the metric based on a gap between a measured value of a parameter and an allocated value of the parameter; and means for performing interference cancelation using results of decoding the selected at least one stream to decode at least one non-selected stream. ### Claim 12 (depends on 11) The apparatus of claim 11, further comprising: means for determining the metric for a stream of data using a measured value of the parameter and an allocated value of the parameter for the stream. ### Claim 13 (depends on 12) The apparatus of claim 12, wherein the metric is averaged over multiple transmissions for the stream. ### Claim 14 (depends on 11) The apparatus of claim 11, wherein the means for selecting at least one of the received streams to decode first is configured to: select a stream corresponding to the largest metric value. ### Claim 15 (depends on 11) The apparatus of claim 11, wherein the parameter comprises signal-to-noise ratio or data rate. ### Claim 16 (depends on 15) The apparatus of claim 15, wherein the allocated signal-to-noise ratio comprises an expected signal-to-noise ratio based on an allocated data rate. ### Claim 17 (depends on 15) The apparatus of claim 15, wherein the allocated data rate for a stream is determined using a number of symbols used for each transmission of the stream and a transport block size. ### Claim 18 An apparatus for wireless communication, comprising: at least one processor configured to: receive at least two streams of data; select at least one of the received streams to decode first, from a comparison of a metric corresponding to at least two of the streams, the metric based on a gap between a measured value of a parameter and an allocated value of the parameter; and perform interference cancelation using results of decoding the selected at least one stream to decode at least one non-selected stream; and a memory coupled to the at least one processor. ### Claim 19 A computer program product for wireless communication, comprising: a computer-readable comprising instructions for: receiving at least two streams of data; selecting at least one of the received streams to decode first, from a comparison of a metric corresponding to at least two of the streams, the metric based on a gap between a measured value of a parameter and an allocated value of the parameter; and performing interference cancelation using results of decoding the selected at least one stream to decode at least one non-selected stream. ### Claim 20 An apparatus for wireless communication, comprising: means for receiving at least first and second streams of data; means for attempting to decode at least a first code block of the first stream; and means for selecting the first stream to decode first and performing interference cancelation using results of decoding the first stream to decode the second stream, if the first code block of the first stream decodes successfully. ### Claim 21 (depends on 20) The method of claim 20, wherein each of the first and the second streams comprises code blocks received within one Long Term Evolution (LTE) subframe. ### Claim 22 (depends on 20) The method of claim 20, wherein the means for attempting to decode the first code block is configured to perform a Cyclic Redundancy Check (CRC) for the first code block. ### Claim 23 An apparatus for wireless communication, comprising: at least one processor configured to: receive at least first and second streams of data; attempt to decode at least a first code block of the first stream; and select the first stream to decode first and performing interference cancelation using results of decoding the first stream to decode the second stream, if the first code block of the first stream decodes successfully; and a memory coupled to the at least one processor. ### Claim 24 A computer program product for wireless communication, comprising: a computer-readable medium comprising instructions for: receiving at least first and second streams of data; attempting to decode at least a first code block of the first stream; and if the first code block of the first stream decodes successfully, selecting the first stream to decode first and performing interference cancelation using results of decoding the first stream to decode the second stream.