Reduced dimension time domain channel estimation in a wireless communication network

摘要

Methods and systems for obtaining improved joint channel estimates for a multi-user, frequency-multiplexed data transmission such as SC-FDMA or OFDM begins by estimating separate contributions of users (and/or other signal sources) to the received signal based on joint frequency domain channel estimates. A reduced data set is obtained by subtracting contributions of one or more users from the received data, leaving only the estimated contributions of the remaining users, with noise and residual estimation error signal. Time domain joint channel estimation is then performed on the reduced data set, which is feasible because the number of users has been reduced. In exemplary embodiments, the reduced data set includes only one estimated user contribution. This process is repeated to obtain time domain estimates for all of the users. The method can be repeated by using the TD channel estimates to re-estimate the user contributions and calculate revised TD channel estimates.

主权项

1. A method of obtaining channel estimates for a frequency-multiplexed data transmission, the method comprising:
receiving, by a receiver unit in wireless communication network, raw time domain data representing a plurality of known reference symbols transmitted over a plurality of frequency-separated subcarriers by a plurality of signal sources; by a signal processing unit:
converting said raw time domain data into frequency domain data;grouping said subcarriers into subcarrier groups, each subcarrier group including K subcarriers, where K is an integer greater than or equal to 1;using the frequency domain data to jointly calculate frequency domain channel estimates for each of the subcarrier groups and signal sources;generating a reduced data set by subtracting from representative data derived from said raw time domain data an estimated contribution arising from at least one of the signal sources according to the frequency domain channel estimates; andcalculating time domain channel estimates from the reduced data set.