Method and apparatus for channel estimation and equalization

摘要

An inverse channel estimation method includes receiving a modulated signal with a pilot. A local reference pilot, matching the received pilot as it was prior to transmission, is divided by a scaled version of the received pilot's power. The division result is scaled again and multiplied with a conjugate value of the received pilot signal, to obtain the inverse channel estimate. Scaling may be performed using bit shifting. The division is performed using a CORDIC algorithm. If multiple pilots are received, interpolation can be performed to provide channel estimates for time and/or frequencies in between. Interpolation can be based on the Farrow method. The received signal may be equalized by multiplying it with the inverse channel estimate.

主权项

1. A method for inverse channel transfer function estimation in a radio receiver, comprising:
in the radio receiver, receiving a modulated signal including a received pilot and storing a frequency-domain representation of the modulated signal in a buffer; in a digital processing unit included in the radio receiver, calculating a value representing a power of the received pilot; determining a bit-shift value; left-shifting the value representing the received pilot's power by the bit-shift value; using a CORDIC algorithm to divide a local reference pilot value by the left-shifted value representing the received pilot's power, obtaining a division result; left-shifting the division result by the bit-shift value; and multiplying the left-shifted division result with a conjugate value of the received pilot to obtain an inverse channel transfer function estimate.