Joint, adaptive control of equalization, synchronization, and gain in a digital communications receiver
View Patent ↗Various aspects and embodiments of the present invention derive statistics of received signal quality and use these statistics to jointly control operation of timing recovery, carrier recovery, automatic gain control, and equalization functions.
1. In a wireless communications receiver having a timing recovery module, carrier recovery module, automatic gain control module, and equalization module, said communications receiver responsive to a received signal to form soft decision samples corresponding to said received signal and hard decision samples corresponding to said received signal, a method for jointly operating said timing recovery module, said carrier recovery module, said automatic gain control module, and said equalization module, said method comprising:
deriving control signals from said soft and hard decision samples, wherein the control signals comprise a candidate error term and a combining weight, wherein said combining weight is based on a normalized difference between said soft and hard decision samples; and
using said control signals to jointly determine operation of said timing recovery module, said carrier recovery module, said automatic gain control module, and said equalization module.
2. The method of claim 1 , wherein the received signal comprises data, the method further comprising:
adjusting a sampling phase and frequency of the data.
3. The method of claim 1 , further comprising:
determining the combining weight by comparing the soft decision sample to a nearest element in a source constellation.