Hitless modulation changes in double capacity links using adaptive coding modulation (ACM)

A processing module for implementation within an outdoor communication unit (ODU), wherein the processing module is configured to adaptively adjust a transmission characteristic, according to a detected condition, using an adaptive coding modulation (ACM) technique, comprising:

• a capacity adaptor configured to substantially eliminate signal losses by adapting a channel capacity of a dual channel wireless link in response to the detected condition;
• and
• one or more processors configured to:
• substantially eliminate VCO pulling within the ODU by ramping down/up a first communication channel of the dual channel wireless link;
• substantially eliminate spectral emissions by performing at least one of:
• a complementary output power ramp up/down technique on the first communication channel and a second communication channel that comprise the dual channel wireless link, and a substantially instantaneous changing technique between a dual channel mode and a single channel mode;
• substantially eliminate LO leakage, and to generate and calibrate DC offset when a switch between the dual channel and single channel mode is taking place;
• adaptively correct I/Q mismatch;
• substantially remove noise from a digital domain to improve an output of the ODU;
• recognize the switch between the dual channel and single channel modes, and to gradually update digital pre-distortion coefficients accordingly;
• substantially eliminate intermodulation of the first and second communication channels when the ODU is operating in the dual channel mode;
• substantially eliminate in-band non-linearity products when the ODU is operating in the single channel mode;
• and
• monitor a frequency selective fading of each of the first and second communication channels, and to adaptively select which of the first and second communication channels is most optimal for transmitting when fading occurs.

A method of optimizing a transmission of data over a dual channel wireless link having a first communication channel and a second communication channel, comprising:

• detecting, at an outdoor communication unit (ODU), an external weather condition and a performance level of each of the first and second communication channels;
• adaptively adjusting, at the ODU, a characteristic of the data and a characteristic of the dual channel wireless link according to the detected external weather condition and the detected performance level of each of the first and second communication channels using an adaptive coding modulation (ACM) technique;
• modulating/demodulating the data at the ODU;
• performing, at the ODU, a mathematical manipulation technique on the data;
• and
• driving, at the ODU, the data over the dual channel wireless link, wherein the ODU and the dual channel wireless link are included within a dual channel microwave backhaul system.