Network side receiver for receiving high velocity transmitted signals

An apparatus for decoding a Physical Uplink Shared Channel (PUSCH) and a Physical Uplink Control Channel (PUCCH) received by a receiver in a high-speed environment, the apparatus comprising:

• a memory configured to store a plurality of instructions;
• and
• processor circuitry coupled to the memory and configured to execute the plurality of instructions to:
• calculate a phase difference of Orthogonal Frequency Division Multiplexing (OFDM) symbols of the PUCCH from:
• OFDM symbols of a first Demodulation Reference Signal (DM-RS) and OFDMA symbols of a second DM-RS of the PUCCH, the OFDMA symbols of the second DM-RS and OFDM symbols of a third DM-RS of the PUCCH, and the OFDM symbols of the first DM-RS and the third DM-RS of the PUCCH received by the receiver, wherein the OFDM symbols of the first DM-RS, the second DM-RS, and the third DM-RS are consecutive DM-RS symbols of the PUCCH;
• correlate the OFDM symbols of the first DM-RS and the second DM-RS, the second DM-RS and the third DM-RS, and the first DM-RS and the third DM-RS;
• determine a doppler shift wherein the doppler shift is proportional to the phase difference across all the DM-RS symbols in the channel;
• report the doppler shift to Layer 2 of a protocol stack;
• compensate channel estimates and data symbols with the doppler shift;
• equalize and demodulate the PUCCH;
• perform a first level of phase correction on the PUSCH received by the receiver by correcting the phase on output samples of an Inverse Discrete Fourier transform (IDFT) from the doppler shift received from Layer 2;
• measure a phase deviation on the output of the first level of phase correction;
• accumulate the measured phase deviation on the output of the first level of phase correction and the doppler shift received from Layer 2, to derive an accumulated phase correction;
• report the accumulated phase correction to Layer 2;
• perform a second level of phase correction according to the measured phase deviation of the output of the first level of phase correction;
• and
• demodulate the PUSCH.

A communication system comprising:

• a mobile device configured to transmit a Physical Uplink Shared Channel (PUSCH) and a Physical Uplink Control Channel (PUCCH) in a high-speed environment;
• and
• an eNodeB configured to:
• calculate a phase difference of Orthogonal Frequency Division Multiplexing (OFDM) symbols of the PUCCH from:
• OFDM symbols of a first Demodulation Reference Signal (DM-RS) and OFDMA symbols of a second DM-RS of the PUCCH, the OFDMA symbols of the second DM-RS and OFDM symbols of a third DM-RS of the PUCCH, and the OFDM symbols of the first DM-RS and the third DM-RS of the PUCCH received by the receiver, wherein the OFDM symbols of the first DM-RS, the second DM-RS, and the third DM-RS are consecutive DM-RS symbols received from the mobile device;
• correlate the OFDM symbols of the first DM-RS and the second DM-RS, the second DM-RS and the third DM-RS, and the first DM-RS and the third DM-RS;
• determine a doppler shift wherein the doppler shift is proportional to the phase difference across the DM-RS symbols in the channel;
• report the doppler shift to Layer 2 of a protocol stack;
• compensate channel estimates and data symbols with the doppler shift;
• equalize and demodulate the PUCCH;
• perform a first level of phase correction on the PUSCH received by the receiver by correcting the phase on output samples of an Inverse Discrete Fourier transform (IDFT) from the doppler shift received from Layer 2;
• measure a phase deviation on the output of the first level of phase correction;
• accumulate the measured phase deviation on the output of the first level of phase correction and the doppler shift received from Layer 2, to derive an accumulated phase correction;
• report the accumulated phase correction to Layer 2;
• perform a second level of phase correction according to the measured phase deviation of the output of the first level of phase correction;
• and
• demodulate the PUSCH.