In an OFDM system the same Walsh code is used at the same time for a
plurality of transmitters. The multiple transmitters can be from the
same, or different devices (e.g., different base stations on the
downlink, different terminals on the uplink). Each subcarrier/antenna
combination will share a similar pilot Walsh code, except for the fact
that the scrambled spread pilot signals will be phase shifted on some
subcarriers of some antennas, based on the subcarrier/antenna
combination.