Energy efficiency in wirless communication systems

A multiple access wireless communication system comprising:

• a plurality of remote terminals;
• at least one base terminal;
• a shared communication channel between said plurality of remote terminals said at least one base terminal;
• and
• a plurality of back channels between said plurality of remote terminals and said base terminal;
• wherein each one of said remote terminals is configured to:
• apply a direct sequence spreading code to a data signal utilizing an associated spreading code and spreading factor to provide a direct sequence spreading spectrum (DSSS) signal;
• and
• transmit said DSSS signal over said shared communication channel to said at least one base terminal;
• wherein said base terminal is configured to:
• receive respective DSSS signals from respective remote terminals;
• despread received DSSS signals utilizing respective spreading codes and spreading factors matching the spreading codes and spreading factors utilized in respective remote terminals;
• wherein, for each one of said received DSSS signals, said base terminal is further configured to dynamically:
• monitor said DSSS signal to estimate said operating quality over time between the remote terminal transmitting said DSSS signal and said base terminal;
• determine that said estimated operating quality has exceeded a limit of a quality margin;
• in response to said estimated operating quality exceeding said quality margin limit, estimate a next data transmission rate that is sufficient to provide an operating quality within said quality margin such that said specified quality of service is met for said next data rate;
• send a command over a back channel to said remote terminal transmitting said DSSS signal for adjusting the spreading factor to adjust the data rate to said estimated next data rate;
• and
• wherein, for each one of said received DSSS signals, said remote terminal transmitting said DSSS signal and said base terminal are configured to dynamically adjust said matching spreading factors to dynamically adjust said data rate to said next data rate such that the amount of data transmitted is substantially maximized whilst providing the specified quality of service for the remote terminal transmitting said DSSS signal.

A method for improving channel utilization in a wireless communication system comprising:

• direct sequence spectrum spreading a data signal by a spreading factor to provide a direct sequence spreading spectrum (DSSS) signal;
• transmitting said DSSS signal from a remote terminal over a communication channel to a base terminal;
• receiving said DSSS signal from said remote terminal;
• despreading said received DSSS signal by a spreading factor matching said spreading factor utilized to spread the data signal;
• and
• dynamically vary the matching spreading factors to adjust the date rate based on an estimation of operating quality over time between the remote terminal and base terminal such that the amount of data transmitted is substantially maximized whilst providing the specified quality of service.

A remote terminal for communicating with a base terminal over a communication channel;

• wherein said remote terminal comprises:
• direct sequence spread spectrum circuitry for applying a direct sequence spreading code to a data signal at a spreading factor to provide a direct sequence spread spectrum (DSSS) signal;
• transmitter circuitry for transmitting said DSSS signal over said communication channel to said base terminal;
• and
• a controller for dynamically vary the spreading factor to adjust the data rate based on an estimation of operating quality over time between the remote terminal and base terminal such that the amount of data being transmitted is substantially maximized whilst providing a specified quality of service.

A base terminal for receiving a DSSS signal transmitted from at least one remote terminal over a communication channel;

• wherein said base terminal comprises:
• receiver circuitry for receiving said DSSS signal;
• direct sequence spread spectrum despreading circuitry for despreading said received DSSS signal by a spreading factor matching said spreading factor utilized to spread the data signal;
• a controller for dynamically varying the spreading factor to adjust the data rate based on an estimation of operating quality over time between the remote terminal and base terminal such that the spreading factor amount of data being received is substantially maximized whilst providing a specified quality of service.