Method and apparatus for simultaneous wideband and narrowband wireless communication

A wireless communication unit for sending and receiving communications by both wideband and narrowband signals, comprising:

• a transmitter comprising means for generating a first narrowband modulated radio frequency signal and a first wideband modulated radio frequency signal, the first wideband modulated radio frequency signal comprising a spread spectrum signal;
• a combiner responsive to the means for generating, for combining the first narrowband modulated radio frequency signal with the first wideband modulated radio frequency signal to form a first composite signal, the first composite signal having a first component derived from the first narrowband modulated radio frequency signal with a first frequency band and a second component derived from the first wideband modulated radio frequency signal with a second frequency band, the second frequency band overlapping the first frequency band, for transmission to at least one other wireless communication unit:
• means for receiving a second composite signal including a second wideband modulated radio frequency signal and a second narrowband modulated radio frequency signal, the means for receiving comprising means for determining the location of the second narrowband modulated radio frequency signal within the second wideband modulated radio frequency signal and means for filtering at least one of the second narrowband modulated radio frequency signal at the determined location and the second wideband modulated radio frequency signal around the determined location of the second narrowband modulated radio frequency signal, wherein the means for determining comprises a transform means for performing a fast Fourier transform (FFT) on the second composite signal to produce frequency domain samples of both the second wideband modulated radio frequency signal and the second narrowband modulated radio frequency signal.

A cellular radiotelephone system for communicating wideband and narrowband signals between at least one base station and subscribers, the system comprising:

• a base station comprising:
• a wideband modulated radio frequency signal generator for generating a first signal having a first frequency band, the first signal comprising a spread spectrum signal;
• a narrowband modulated radio frequency signal generator for generating a second signal having a second frequency band, the second frequency band being narrower than the first frequency band;
• a combiner combining the first and second signals to form a composite modulated radio frequency signal;
• a transmitter transmitting the composite modulated radio frequency signal to a plurality of subscribers;
• means for controlling signal power of the second
• wherein the means for controlling signal power comprises:
• means for detecting signal power of the second signal and signal power of the first signal, and
• means for controlling the narrowband modulated radio frequency signal generator for adjusting the signal power of the second signal so as to maintain the signal power of the second signal within a predetermined range of ratios to the signal power of the first signal required to maintain at least a predetermined carrier to interference (C/I) level of the second signal for a subscriber receiving the second signal.

A cellular radiotelephone system for communicating wideband and narrowband signals between at least one base station and subscribers, the system comprising:

• a base station comprising;
• a wideband modulated radio frequency signal generator for generating a first signal having a first frequency band, the first signal comprising a spread spectrum signal;
• a narrowband modulated radio frequency signal generator for generating a second signal having a second frequency band, the second frequency band being narrower than the first frequency band;
• a combiner combining the first and second signals to form a composite modulated radio frequency signal;
• a transmitter transmitting the composite modulated radio frequency signal to a plurality of subscribers;
• and
• means for reassigning a subscriber receiving communications via the second signal to receive communications via a narrowband signal having a third frequency band which is outside of the first frequency band.

A system for receiving communications via wideband signals from wideband signal subscribers to a fixed station, and via narrowband signals from narrowband signal subscribers to the fixed station, the system comprising:

• a receiver detecting a composite wideband spread spectrum modulated radio frequency signal composed of at least a first one of the narrowband signals having a frequency band, and a first one of the wideband signals from a first one of the wideband signal subscribers, the first one of the wideband signals having a frequency band wider than and overlapping the frequency band of the first narrowband signal;
• and
• separating means including a first filter and a second filter, the separating means connected to the receiver means for separating and recovering the first narrowband signal and the first wideband signal,
• wherein the first filter comprises a first digital processor for frequency transforming the composite wideband spread spectrum modulated radio frequency signal, determining a frequency of the first narrowband signal, filtering the transformed composite wideband spread spectrum modulated radio frequency signal at the determined frequency of the first narrowband signal, and inverse transforming the filtered composite wideband spread spectrum modulated radio frequency signal to recover the first wideband signal.

A system for receiving communications via wideband signals from wideband signal subscribers to a fixed station, and via narrowband signals from narrowband signal subscribers to the fixed station;

• the system comprising:
• a receiver detecting a composite wideband spread spectrum modulated radio frequency signal composed of at least a first one of the narrowband signals having a frequency band, and a first one of the wideband signals from a first one of the wideband signal subscribers, the first one of the wideband signals having a frequency band wider than and overlapping the frequency band of the first narrowband signal;
• and
• separating means including a first filter and a second filter, the separating means connected to the receiver means for separating and recovering the first narrowband signal and the first wideband signal;
• wherein the second filter comprises a second digital processor for frequency transforming the composite wideband spread spectrum modulated radio frequency signal, determining a frequency of the first narrowband signal, filtering the transformed composite wideband spread spectrum modulated radio frequency signal at the determined frequency of the first narrowband signal, and inverse transforming the filtered composite wideband spread spectrum modulated radio frequency signal to recover the first narrowband signal.

A system for receiving communications via wideband signals from wideband signal subscribers to a fixed station, and via narrowband signals from narrowband signal subscribers to the fixed station, the system comprising:

• a receiver detecting a composite wideband spread spectrum modulated radio frequency signal composed of at least a first one of the narrowband signals having a frequency band, and a first one of the wideband signals from a first one of the wideband signal subscribers, the first one of the wideband signals having a frequency band wider than and overlapping the frequency band of the first narrowband signal;
• separating means connected to the receiver means for separating and recovering the first narrowband signal and the first wideband signal:
• and
• means for reassigning a subscriber transmitting communications via the first narrowband signal to receiving communications via a second narrowband signal having a frequency band which is outside of the frequency band of the first wideband signal.

A cellular radiotelephone system for simultaneously communicating wideband and narrowband signals between at least one base station and subscribers, the system comprising:

• a base station transmitter circuitry comprising:
• a wideband signal generator operable for generating a first wideband signal characterized by a first frequency band;
• a narrowband signal generator operable for generating a first narrowband signal characterized by a second frequency band within the first frequency band;
• a combiner coupled to the wideband and narrowband signal generators, being operable for combining the first narrowband and first wideband signals and outputting a first composite wideband signal;
• an amplifier and antenna connected to the combiner, being operable for amplifying the first composite wideband signal and transmitting the amplified first composite wideband signal to a plurality of subscribers;
• and
• a base station receiver circuitry comprising:
• an RF front end circuitry operable for receiving a second composite wideband signal having at least a second narrowband signal embedded in a second wideband signal;
• an analog to digital converter connected to the RF front end circuitry operable for outputting a digitized second composite wideband signal;
• a narrowband signal processing circuit connected to the analog to digital converter, and comprising a downmixing and decimation filter operable for recovering the second narrowband signal;
• and
• a wideband signal processing circuit connected to the analog to digital converter, and comprising a transformation circuit connected to the converter operable for transforming the digitized second composite wideband signal into a frequency domain composite signal, a narrowband signal detector connected to the transformation circuit operable for determining the frequency of the second narrowband signal, a filter connected to the narrowband signal detector operable for filtering the frequency domain composite signal at the determined frequency of the second narrowband signal and outputting a frequency domain representation of the second wideband signal, and inverse transformation circuitry connected to the filter operable for inverse transforming the frequency domain representation of the second wideband signal to recover the second wideband signal.

A method for wireless communications, comprising:

• modulating first information into a narrowband signal for communication with a first remote unit having a narrowband demodulator;
• modulating second information into a wideband signal for communication with a second remote unit having a wideband demodulator:
• embedding the narrowband signal within the wideband signal to form a composite wideband signal;
• transmitting the composite wideband signal to the first and second remote units;
• detecting signal power levels of the narrowband signal and the wideband signal;
• determining a predetermined ratio of the signal power level of the narrowband signal to the signal power level of the wideband signal required to maintain at least a predetermined carrier to interference (C/I) level of the narrowband signal for a subscriber receiving the narrowband signal;
• and
• adjusting the signal power level of the narrowband signal such that the predetermined ratio is maintained.