Uplink channel estimation using a signaling channel

摘要

Techniques for efficiently deriving uplink channel estimates without consuming much additional uplink resources are described. A user equipment (UE) may send a request for uplink resources on a request channel (REQCH) whenever the UE desires to transmit data on the uplink. The UE may send the REQCH on a set of subcarriers and from multiple antennas, e.g., send REQCH data on data subcarriers and pilot on pilot subcarriers. A node B may receive the request, estimate the complex channel gains for the pilot subcarriers based on received pilot symbols, and coherently demodulate received data symbols based on the channel gain estimates. The Node B may estimate the complex channel gains for the data subcarriers based on demodulated data symbols and derive a channel estimate for each UE antenna based on the channel gain estimates for the pilot and data subcarriers. The Node B may use the channel estimates for MIMO scheduling, subband scheduling, and rate selection.

主权项

1. An apparatus comprising:
a processor configured to:
determine a set of subcarriers to use for a signaling channel;send a message on the signaling channel on the set of subcarriers and from multiple antennas, wherein the set of subcarriers belongs in at least two time frequency blocks distributed across system bandwidth, and wherein the at least two time frequency blocks hop across the system bandwidth in different time intervals, and wherein the message is a request for uplink resources, and wherein the processor is configured to send the message from the multiple antennas simultaneously in a time interval;send pilot symbols on the set of subcarriers; andreceive an assignment, based on the request for uplink resources, of time frequency resources shared with at least one other apparatus, wherein the assignment is selected based on the sent pilot symbols and other pilot symbols transmitted from the at least one other apparatus; and a memory coupled to the processor.