Systems and methods for high rate ofdm communications using first and second cyclic prefix lengths

A communications system comprising an OFDM transceiver capable of:

• transmitting or receiving, over a first communication channel using a first cyclic prefix length, a first plurality of OFDM symbols that carry data bytes;
• detecting a change in one or more channel conditions;
• and
• transmitting or receiving, over a second communication channel using a second cyclic prefix length, a second plurality of OFDM symbols that carry data bytes;
• wherein:
• the first cyclic prefix length is shorter than the second cyclic prefix length,
• the first communication channel has a shorter impulse response length than the second communication channel,
• the first cyclic prefix length is based on a length of an impulse response for the first communication channel, and
• the second cyclic prefix length is based on a length of an impulse response for the second communication channel.

In an OFDM transceiver, a method comprising:

• transmitting or receiving, over a first communication channel using a first cyclic prefix length, a first plurality of OFDM symbols that carry data bytes;
• detecting a change in one or more channel conditions;
• and
• transmitting or receiving, over a second communication channel using a second cyclic prefix length, a second plurality of OFDM symbols that carry data bytes,
• wherein:
• the first cyclic prefix length is shorter than the second cyclic prefix length,
• the first communication channel has a shorter impulse response length than the second communication channel,
• the first cyclic prefix length is based on the length of an impulse response for the first communication channel, and
• the second cyclic prefix length is based on the length of the impulse response for the second communication channel.

A communications system comprising an OFDM transceiver capable of:

• transmitting or receiving, over a first communication channel using a first cyclic prefix length, a first plurality of OFDM symbols that carry data bytes;
• and
• changing from a first data rate to a second data rate by transmitting or receiving, over a second communication channel using a second cyclic prefix length, a second plurality of OFDM symbols that carry data bytes,
• wherein:
• the first cyclic prefix length is shorter than the second cyclic prefix length,
• the first communication channel has a shorter impulse response length than the second communication channel,
• the first cyclic prefix length is based on the length of impulse response of the first communication channel, and
• the second cyclic prefix length is based on the length of the impulse response of the second communication channel.

In an OFDM transceiver, a method comprising:

• transmitting or receiving, over a first communication channel using a first cyclic prefix length, a first plurality of OFDM symbols that carry data bytes;
• and
• changing from a first data rate to a second data rate by transmitting or receiving, over a second communication channel using a second cyclic prefix length, a second plurality of OFDM symbols that carry data bytes,
• wherein:
• the first cyclic prefix length is shorter than the second cyclic prefix length,
• the first communication channel has a shorter impulse response length than the second communication channel,
• the first cyclic prefix length is based on the length of impulse response of the first communication channel, and
• the second cyclic prefix length is based on the length of the impulse response of the second communication channel.