Method and apparatus for reducing amplitude variations and interference in communication signals, such as in wireless communication signals employing inserted pilot symbols

In a communication system having a base station and a plurality of user stations that exchange communication signals with the base station, an apparatus for reducing transmission signal power of transmitted communication signals, the apparatus comprising:

• means for receiving channel data for transmission on a plurality of channels, wherein the channel data includes pilot symbol data;
• means for combining orthogonal codes with the received channel data, wherein each orthogonal code has at least one common chip position, and wherein the common chip position has a same value for each orthogonal code;
• and
• means, coupled to the means for combining, for altering the common chip position of at least one of the orthogonal codes to reduce a combined amplitude resulting from simultaneous transmission and addition of the common chip position for the plurality of channels.

In a communication system having a base station and a plurality of user stations that exchange communication signals with the base station, an apparatus for reducing transmission signal power of transmitted communication signals, the apparatus comprising:

• an input node that receives channel data for transmission on a plurality of channels, wherein the channel data includes pilot symbol data;
• an orthogonal code generator combining orthogonal codes, wherein each orthogonal code has at least one common chip position, and wherein the common chip position has a same value for each orthogonal code;
• and
• a common chip position altering circuit, coupled to the input node and the orthogonal code generator, that alters the common chip position of at least one of the orthogonal codes before combining the channel data combined with the orthogonal codes to reduce a combined amplitude resulting from addition of the common chip position for the plurality of channels.

In a communication system having a base station and a plurality of user stations that exchange signals with the base station, an apparatus for reducing transmission signal power of transmitted signals, the apparatus comprising:

• an input node that receives data for transmission on a plurality of channels, wherein the data includes pilot symbols;
• an altered orthogonal code generator, wherein each of a plurality of unaltered orthogonal codes have at least one common chip position having a same value, and wherein the altered orthogonal code generator alters at least some of the unaltered orthogonal codes by a phase value between 0 and 360 degrees to produce phase altered orthogonal codes;
• and
• a combining circuit that combines at least some of the pilot symbols for some of the plurality of channels with the phase altered orthogonal codes to reduce a combined amplitude resulting from addition of the common chip position for the plurality of channels.

In a communication system having a base station and a plurality of user stations that exchange signals with the base station, an apparatus for reducing transmission signal power of transmitted signals, the apparatus comprising:

• an input node that receives data for transmission on a plurality of channels, wherein the data includes pilot symbols;
• an altered orthogonal code generator, wherein each of a plurality of unaltered orthogonal codes has at least one common chip position having a same value, and wherein the altered orthogonal code generator attenuates the common chip position in at least some of the unaltered orthogonal codes to produce altered orthogonal codes;
• and
• a combining circuit that combines at least some of the pilot symbols for some of the plurality of channels with the altered orthogonal codes to reduce a combined amplitude resulting from addition of the common chip position for the plurality of channels.