Efficient multicarrier filter

A filter for a wireless communications system employing a multi-carrier signal comprising:

• first means for extracting carrier signal components from the multi-carrier signal;
• and
• second means for filtering the carrier signal components to generate a demodulated and filtered multi-bandwidth signal,
• wherein the second means includes an Infinite Impulse Response (IIR) filter for matching a pulse shape of the multi-carrier signal, and
• wherein the second means further includes means for compensating for pre-equalization effects on the multi-carrier signal to minimize phase non-linearity, and
• wherein the IIR filter is a 5th order elliptic IIR filter employed as a 1× lowpass filter for lowpass filtering the carrier signal components, where the carrier signal components define three data streams separated in frequency, and
• wherein the IIR filter has a cascade direct form II structure, and
• further including means for avoiding overflow at nodes of the IIR filter.

A receiver for a wireless communications system comprising:

• a receive section having a Radio Frequency (RF) to Intermediate Frequency (IF) circuit and an IF to baseband circuit;
• a multi-carrier filter in communication with the receive section, the multi-carrier filter having:
• a first lowpass filter for filtering a first data stream,
• a phase accumulator coupled to a rotator,
• a second lowpass filter for filtering a second data stream output by the rotator, and
• a third lowpass filter for filtering a third data stream output by said rotator;
• and
• a Mobile Station Modem (MSM) coupled to the first lowpass filter, the second lowpass filter, and the third lowpass filter.