# US 9,438,358 B2 · Receiver unit and method for correcting a value of a receive signal strength indicator > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,438,358 B2 - Document ID: US9438358B2 - Status: Granted - Kind: B2 - Application number: 14/423,724 - Filed: 2012-09-14 - Published: 2015-07-23 - Granted: 2016-09-06 - Earliest claimed: 2012-09-14 - Assignees: Freescale Semiconductor, Inc. - Applicants: Dominique Delbecq; Fares Jaoude - Inventors: Dominique Delbecq; Fares Jaoude - Web page: https://patentgrep.com/patent/US9438358B2 ## CPC - H04B 17/22: {for calibration of the receiver components} - H03G 3/005: {Control by a pilot signal (H03G3/001 takes precedence)} - H04B 1/12: Neutralising, balancing, or compensation arrangements - H04B 1/16: Circuits - H04B 17/0085: {using test signal generators} - H04B 17/318: Received signal strength - H04B: TRANSMISSION - H03G: CONTROL OF AMPLIFICATION ## Abstract A receiver unit comprising a mixer, a test signal unit, a multiplexer unit, an amplifier unit, a signal strength unit, and a digital control unit is described. The mixer may be arranged to downconvert a received radio-frequency signal to an intermediate frequency, thereby generating a reception signal having the intermediate frequency. The multiplexer unit may be connected to the mixer and to the test signal unit and arranged to select, among the reception signal and a test signal, a multiplexer output signal in dependence on an operating signal. The amplifier unit may be connected to the multiplexer unit and arranged to amplify the multiplexer output signal, thereby generating an amplified signal. The signal strength unit may be connected to the amplifier unit and arranged to generate a signal strength indicator indicative of a signal strength of the amplified signal. The control unit may be connected to the signal strength unit and arranged to generate the operating signal in accordance with an operating cycle, the operating cycle comprising one or more test phases and a reception phase. The test signal unit may be connected to the control unit and arranged to generate the test signal in dependence on the operating signal, the test signal having the intermediate frequency. The control unit may be further arranged to: gather, in each of the test phases, a test value of the signal strength indicator, thus gathering one or more test values; determine a numerical transformation on the basis of the one or more test values; gather, in the reception phase, a reception value of the signal strength indicator; and compute a corrected signal strength value by applying the transformation to the reception value. ## Claims ### Claim 1 A receiver unit, comprising a mixer, a test signal unit, a multiplexer unit, an amplifier unit, a signal strength unit, and a digital control unit; said mixer arranged to downconvert a received radio-frequency signal to an intermediate frequency, thereby generating a reception signal having said intermediate frequency; said multiplexer unit connected to said mixer and to said test signal unit and arranged to select, among said reception signal and a test signal, a multiplexer output signal in dependence on an operating signal; said amplifier unit connected to said multiplexer unit and arranged to amplify said multiplexer output signal, thereby generating an amplified signal; said signal strength unit connected to said amplifier unit and arranged to generate a signal strength indicator indicative of a signal strength of said amplified signal; said control unit connected to said signal strength unit and arranged to generate said operating signal in accordance with an operating cycle, said operating cycle comprising one or more test phases and a reception phase; said test signal unit connected to said control unit and arranged to generate said test signal in dependence on said operating signal, said test signal having said intermediate frequency; said control unit further arranged to: gather, in each of said test phases, a test value of said signal strength indicator; determine a numerical transformation on the basis of said one or more test values; gather, in said reception phase, a reception value of said signal strength indicator; and compute a corrected signal strength value by applying said transformation to said reception value. ### Claim 2 (depends on 1) The receiver unit of claim 1, said control unit arranged to control a gain of said amplifier unit such that said gain is stationary during each of said test phases. ### Claim 3 (depends on 1) The receiver unit of claim 1, said control unit arranged to set a gain of said amplifier unit to a first value in a first one of said test phases and to a different second value in a second one of said test phases. ### Claim 4 (depends on 1) The receiver unit of claim 1, said transformation depending parametrically on one or more parameters, said control unit arranged to fit said parameters such that said transformation applied to said one or more test signal strength values reproduces one or more expected signal strength values to a best possible extent. ### Claim 5 (depends on 4) The receiver unit of claim 4, said control unit comprising a memory unit, said expected signal strength values or equivalent values stored in said memory unit. ### Claim 6 (depends on 5) The receiver unit of claim 5, said memory unit being a read-only memory unit. ### Claim 7 (depends on 5) The receiver unit of claim 5, said memory unit being a read-and-write memory unit. ### Claim 8 (depends on 1) The receiver unit of claim 1, wherein said transformation is: YT=A*YM+B A being a slope, B being an offset, said control unit arranged to compute said slope A and said offset B on the basis of said one or more test signal strength values and one or more expected signal strength values. ### Claim 9 (depends on 1) The receiver unit of claim 1, said test signal having a stationary amplitude during each of said test phases. ### Claim 10 (depends on 9) The receiver unit of claim 9, said stationary amplitude having a first value during a first one of said test phases and a different second value during a second one of said test phases. ### Claim 11 (depends on 1) The receiver unit of claim 1, said control unit further arranged to control a gain of said amplifier unit during said reception phase in dependence on said corrected signal strength value. ### Claim 12 A method of generating a corrected signal strength indicator, comprising: downconverting a received radio-frequency signal to an intermediate frequency, thereby generating a reception signal having said intermediate frequency; selecting, among said reception signal and a test signal, a multiplexer output signal in dependence on an operating signal; amplifying said multiplexer output signal, thereby generating an amplified signal; generating a signal strength indicator indicative of a signal strength of said amplified signal; generating said operating signal in accordance with an operating cycle, said operating cycle comprising one or more test phases and a reception phase; generating said test signal in dependence on said operating signal, said test signal having said intermediate frequency; gathering, in each of said test phases, a test value of said signal strength indicator; determining a numerical transformation on the basis of said one or more test values; gathering, in said reception phase, a reception value of said signal strength indicator; and computing a corrected signal strength value by applying said transformation to said reception value.