Abstract: A GNSS receiver having test signal based failure detection, comprises: a signal generator configured to generate a test signal, the test signal having characteristics of a GNSS signal; one of more amplifiers configured to amplify the test signal; a signal chain configured to receive the amplified test signal at an input node of the signal chain and process the received test signal; and a signal processor configured to: monitor the test signal by: obtaining one or more output signals of the device at one or more output node; recovering the test signal from the one or more output signals, and determining whether one or more errors occurred based on parameters of the recovered test signal based on parameters of the recovered test signal; identify a device failure based on the determined one or more errors; and generate notifications relating to the device failure.

Abstract: A GNSS receiver having test signal based failure detection, comprises: a signal generator configured to generate a test signal, the test signal having characteristics of a GNSS signal; one of more amplifiers configured to amplify the test signal; a signal chain configured to receive the amplified test signal at an input node of the signal chain and process the received test signal; and a signal processor configured to: monitor the test signal by: obtaining one or more output signals of the device at one or more output node; recovering the test signal from the one or more output signals, and determining whether one or more errors occurred based on parameters of the recovered test signal based on parameters of the recovered test signal; identify a device failure based on the determined one or more errors; and generate notifications relating to the device failure.

Abstract: In accordance with an example embodiment of the present invention, an apparatus comprises a processor and a memory including computer program code, wherein the memory and the computer program code, with the processor, are configured with the processor to cause the apparatus to receive a reference signal (302), estimate difference between actual Eigen directions and precoding matrix based on the received reference signal (304), generate a feedback based on the result of the estimation (306), and transmit the feedback (38), wherein the feedback indicates at least one of the result of the estimation, whether a multi-user communication mode is desired or whether the feedback should be combined with another indication in order to determine whether a multi-user communication mode is desired (306). Methods and computer readable media are also described.

Abstract: A method, apparatus, and computer program for carrying out channel sounding are provided. Said method comprises: causing, by an apparatus, transmission of a request for space-time channel sounding to at least one unassociated access node; receiving, in the apparatus as a multi-antenna transmission and in response to said request, at least one message comprising space-time sounding information from at least one unassociated access node; determining, by the apparatus, at least one parameter describing space-time channel quality from the received space-time sounding information; and causing, by the apparatus, transmission of the at least one determined parameter to an associated access node or causing selection of an unassociated access node for further communication based at least partly on the determined at least one parameter.

Abstract: A method, apparatus, and computer program for carrying out channel sounding are provided. Said method comprises: causing, by an apparatus, transmission of a request for space-time channel sounding to at least one unassociated access node; receiving, in the apparatus as a multi-antenna transmission and in response to said request, at least one message comprising space-time sounding information from at least one unassociated access node; determining, by the apparatus, at least one parameter describing space-time channel quality from the received space-time sounding information; and causing, by the apparatus, transmission of the at least one determined parameter to an associated access node or causing selection of an unassociated access node for further communication based at least partly on the determined at least one parameter.