Methods and systems for OFDM using code division multiplexing

摘要

In some embodiments of the invention, OFDM symbols are transmitted as a plurality of clusters. A cluster includes a plurality of OFDM sub-carriers in frequency, over a plurality of OFDM symbol durations in time. Each cluster includes data as well as pilot information as a reference signal for channel estimation. In some embodiments, a plurality of clusters collectively occupy the available sub-carrier set in the frequency domain that is used for transmission. In some embodiments of the invention data and/or pilots are spread within each cluster using code division multiplexing (CDM). In some embodiments pilots and data are separated by distributing data on a particular number of the plurality of OFDM symbol durations and pilots on a remainder of the OFDM symbol durations. CDM spreading can be performed in time and/or frequency directions.

主权项

1. A mobile terminal comprising:
one or more antennas configured to receive a first signal from a wireless channel, wherein the first signal includes a cluster, wherein the cluster corresponds to a plurality of subcarriers in frequency and a plurality of transmit symbol intervals in time; and a receiver configured to:
recover first pilot symbols from the cluster by applying a first code-division multiplexing (CDM) code to a first subset of locations within the cluster; andgenerate channel estimates for the wireless channel based on the first pilot symbols.