Channel estimation in a wireless communication system

Radio equipment for tap separated channel estimation in a wireless communication system, the radio equipment comprising:

• communication circuitry;
• and
• processing circuitry configured to:
• obtain a channel estimate of a radio channel over which a reference signal is received;
• separate the channel estimate into channel estimate components that correspond to respective channel taps;
• compensate the channel estimate components for Doppler shifts respectively associated with the channel taps to which the channel estimate components correspond;
• process the compensated channel estimate components separately, wherein said processing comprises filtering, interpolating, and/or extrapolating;
• de-compensate the processed channel estimate components for the respective Doppler shifts;
• and
• form a combined channel estimate of the radio channel by combining the de-compensated channel estimate components.

A method performed by radio network equipment configured for use in a wireless communication system, the method comprising:

• receiving from a user equipment signaling indicating whether or not a user equipment has a certain capability, wherein the certain capability comprises:
• tap separated channel estimation in which the user equipment compensates channel estimate components for Doppler shifts respectively associated with channel taps to which the channel estimate components correspond and filters, interpolates, and/or extrapolates the compensated channel estimate components separately;
• meeting a certain demodulation performance requirement while the user equipment is moving at a speed within a certain range;
• or
• performing channel estimation using a certain one of multiple possible reference signal patterns with different respective time domain reference symbol densities;
• and
• determining, based on the received signaling and from multiple possible reference signal patterns with different respective time domain reference symbol densities, a reference signal pattern of a reference signal to transmit to the user equipment;
• and
• transmitting the reference signal with the determined reference signal pattern to the user equipment.

Radio network equipment for tap separated channel estimation in a wireless communication system, the radio network equipment comprising:

• communication circuitry;
• and
• processing circuitry configured to:
• receive from a user equipment signaling indicating whether or not a user equipment has a certain capability, wherein the certain capability comprises:
• tap separated channel estimation in which the user equipment compensates channel estimate components for Doppler shifts respectively associated with channel taps to which the channel estimate components correspond and filters, interpolates, and/or extrapolates the compensated channel estimate components separately;
• meeting a certain demodulation performance requirement while the user equipment is moving at a speed within a certain range;
• or
• performing channel estimation using a certain one of multiple possible reference signal patterns with different respective time domain reference symbol densities;
• and
• determine, based on the received signaling and from multiple possible reference signal patterns with different respective time domain reference symbol densities, a reference signal pattern of a reference signal to transmit to the user equipment;
• and
• transmit the reference signal with the determined reference signal pattern to the user equipment.