Methods and apparatus for ingress mitigation in cable communication systems, and cable communication systems and methods having increased upstream capacity

Cable communication systems and methods to provide voice and/or data services to subscriber premises via a cable plant that conveys upstream information over an upstream path bandwidth, and a cable modem system including one or more demodulation tuners to receive and demodulate one or more upstream radio frequency (RF) signals. An RF signal includes an encoded carrier wave having a carrier frequency of between approximately 5 MHz and 25 MHz that is modulated using quadrature amplitude modulation (QAM) with voice and/or data information constituting at least some of the upstream information. A modulation order of the QAM for the first upstream RF signal is at least 32 and as high as at least 256, and at least one demodulation tuner of the cable modem system is configured to receive and demodulate the first upstream RF signal.