Receiver with doppler tolerant equalization

A mobile communication device configured to:

• extract one or more pilot signals from a segment of a received signal;
• perform Minimum Mean Square Error (MMSE) filtering on said extracted pilot signals, wherein said filter provides estimated pilot signal impulse responses;
• estimate the amplitudes of one or more path components of said estimated pilot signal impulse responses;
• estimate the phases of one or more path components of said estimated pilot signal impulse responses;
• and
• combine said estimated amplitudes and said estimated phases of said path components of said pilot signal impulse responses, wherein said combination provides an estimated channel impulse response.

A method to equalize a Doppler shifted received signal, said method comprising:

• extracting one or more pilot signals from a segment of said received signal;
• performing MMSE filtering on said extracted pilot signals, wherein said filtering provides estimated pilot signal impulse responses;
• estimating the amplitudes of one or more path components of said estimated pilot signal impulse responses;
• estimating the phases of one or more path components of said estimated pilot signal impulse responses;
• and
• combining said estimated amplitudes and said estimated phases of said path components of said pilot signal impulse responses, wherein said combination provides an estimated channel impulse response.

A computer-readable storage medium having instructions stored thereon which when executed by a processor result in the following operations for estimating receiver noise variance, said operations comprising:

• extracting one or more pilot signals from a segment of said received signal;
• performing MMSE filtering on said extracted pilot signals, wherein said filtering provides estimated pilot signal impulse responses;
• estimating the amplitudes of one or more path components of said estimated pilot signal impulse responses;
• estimating the phases of one or more path components of said estimated pilot signal impulse responses;
• and
• combining said estimated amplitudes and said estimated phases of said path components of said pilot signal impulse responses, wherein said combination provides an estimated channel impulse response.

A system to equalize a Doppler shifted received signal, said system comprising:

• a processor;
• a memory coupled to said processor;
• a user interface coupled to said processor;
• an antenna;
• a pilot extraction circuit coupled to said antenna and to said processor, said pilot extraction circuit configured to extract one or more pilot signals from a segment of said received signal;
• an impulse response estimation filter circuit coupled to said pilot extraction circuit, said impulse response estimation filter circuit configured to perform MMSE filtering on said extracted pilot signals, wherein said filter provides estimated pilot signal impulse responses;
• a path amplitude estimation circuit coupled to said impulse response estimation filter circuit, said path amplitude estimation circuit configured to estimate the amplitudes of one or more path components of said estimated pilot signal impulse responses;
• a path phase estimation circuit coupled to said impulse response estimation filter circuit, said path phase estimation circuit configured to estimate the phases of one or more path components of said estimated pilot signal impulse responses;
• and
• a channel impulse response estimation circuit coupled to said path amplitude estimation circuit and said path phase estimation circuit, said channel impulse response estimation circuit configured to combine said estimated amplitudes and said estimated phases of said path components of said pilot signal impulse responses, wherein said combination provides an estimated channel impulse response.