An estimate of one of a DSL data transmission signal or DSL synch symbol transmission signal is removed from the received probing signal to recover the reflected probing signal.

The return signal is generated by reflection of the probing signal against the static element.

In one implementation, the method may include sending a survey signal to a subsurface region, wherein the survey signals is a first electromagnetic signal and sending a diagnostic signal to the receiver.

According to one aspect, a method includes directing at least one low power node to transmit a probing signal, where the probing signal includes least one code.

Each downlink probing signal is a virtual antenna port with respect to the mobile user equipment.

During a period of the probing phase, a probing signal from each antenna may be transmitted during a respective time interval.

A response of the network to the probe signal combined with the recurrent transmissions is then detected.

A Node B may receive each probing signal and determine channel quality information.

The method receives an uplink probing signal from the mobile user equipment.

The system uses a piezoelectric transducer to launch an ultrasonic probe signal into the pipe.

The channel quality is based on a power of the probing signal received by the wireless terminal.

The recovered reflected probing signal is processed to determine characteristics information of the twisted pair telephone line.

The present invention relates to a method and apparatus for transmitting/receiving a sounding reference signal in a wireless communication system.

A method and device for spectrum comb signaling notification and for sounding reference signal transmission.

Reflected ultrasonic signals are captured in a transducer, which can be the same transducer that launched the probe signal.