Range extension techniques for a wireless local area network

摘要

Techniques for extending transmission range in a WLAN are described. In an aspect, a receiving station determines the frequency error between a transmitting station and the receiving station based on one or more initial packet transmissions and corrects this frequency error for subsequent packet transmissions received from the transmitting station. The residual frequency error is small after correcting for the frequency error and allows the receiving station to perform coherent accumulation/integration over a longer time interval to detect for a packet transmission. The longer coherent accumulation interval improves detection performance, especially at low SNRs for extended transmission range. The techniques may be used whenever the receiving station knows the identity of the transmitting station, e.g., if the subsequent packet transmissions are scheduled. Other aspects, features, and embodiments are also claimed and described.

主权项

1. An apparatus comprising:
at least one processor configured to despread samples with a sequence of more than 11 chips to obtain despread symbols, and to detect for a preamble transmitted in a wireless local area network (WLAN) based on the despread symbols by deriving products of despread symbols for at least two delays, performing correlation of the products for each delay with expected values for the delay, combining correlation results for the at least two delays, and detecting for the preamble based on the combined correlation results; and a memory coupled to the at least one processor.