Method and apparatus for implementing a received signal quality measurement in a radio communication system

A controller for implementing a received signal quality measurement in a radio communication system for delivering a message comprising a message portion intended for a portable subscriber unit in a coverage zone of a plurality of coverage zones, the controller comprising:

• a processing system for controlling operation of the controller;
• an input interface coupled to the processing system for accepting the message from a message originator;
• a transmitter controller coupled to the processing system for controlling a plurality of transmitters positioned in the plurality of coverage zones, and
• a receiver coupled to the processing system for receiving a response from the portable subscriber unit,
• wherein the processing system is programmed for making, for each coverage zone of a group comprising the coverage zone and other coverage zones that are first tier co-channel interferers of the coverage zone, an assignment of a silence slot in one of a plurality of predetermined synchronized signal quality measurement (SQM) slots, wherein the assignment is made such that within the group no two coverage zones have the silence slot assigned to an identical one of the plurality of predetermined synchronized SQM slots, and
• wherein the processing system is further programmed for controlling the plurality of transmitters to transmit a silent modulation signal from each of selected ones of the coverage zones of the group in the silence slot assigned thereto, and to transmit a predetermined modulation signal from the selected ones of the coverage zones of the group in a remainder of the plurality of predetermined synchronized SQM slots not assigned thereto as the silence slot, and
• wherein the processing system is further programmed for thereafter controlling the plurality of transmitters to transmit from the coverage zone the message portion intended for the portable subscriber unit, wherein the message portion is transmitted proximate the SQM slots.

A portable subscriber unit for implementing a received signal quality measurement in a radio communication system for delivering a message comprising a message portion intended for the portable subscriber unit in a coverage zone of a coverage area partitioned into coverage zones, the portable subscriber unit comprising:

• a receiver for receiving transmissions from a group of the coverage zones during a plurality of predetermined synchronized signal quality measurement (SQM) slots;
• a processing system coupled to the receiver for controlling operation of the portable subscriber unit;
• a power measurement element coupled to the receiver for measuring mean RMS power received in each of the plurality of predetermined synchronized SQM slots;
• and
• a transmitter coupled to the processing system for sending acknowledgment responses to a fixed portion of the radio communication system,
• wherein the processing system is programmed for making a determination of which one of the plurality of predetermined synchronized SQM slots is a home silence slot transmitted from the coverage zone in which the portable subscriber unit is located, the determination made by controlling the power measurement element to examine the mean RMS power received in each of the plurality of predetermined synchronized SQM slots.

A method of implementing a received signal quality measurement in a radio communication system for delivering a message portion intended for a portable subscriber unit in a coverage zone of a plurality of coverage zones, the method comprising in a fixed portion of the radio communication system the steps of:

• (a) making, for each coverage zone of a group comprising the coverage zone and other coverage zones that are first tier co-channel interferers of the coverage zone, a first assignment of a tone slot in one of a plurality of predetermined synchronized signal quality measurement (SQM) slots, wherein the first assignment is made such that within the group no two coverage zones have the tone slot assigned to an identical one of the plurality of predetermined synchronized SQM slots;
• (b) making for all the coverage zones of the group a second assignment of a quiet slot, the quiet slot assigned to a predetermined identical one of the plurality of predetermined synchronized SQM slots for all the coverage zones of the group;
• (c) transmitting a predetermined modulation signal from each of selected ones of the coverage zones of the group in the tone slot assigned thereto, and transmitting a silent modulation signal from the selected ones of the coverage zones of the group in a remainder of the plurality of predetermined synchronized SQM slots not assigned thereto as the tone slot;
• and
• (d) transmitting from the coverage zone the message portion intended for the portable subscriber unit, wherein the message portion is transmitted proximate the SQM slots.

A portable subscriber unit for implementing a signal quality measurement in a radio communication system for delivering a message portion intended for the portable subscriber unit in a coverage zone of a plurality of coverage zones, the portable subscriber unit comprising:

• a receiver for receiving transmissions from a group of the coverage zones during a plurality of predetermined synchronized signal quality measurement (SQM) slots;
• a processing system coupled to the receiver for controlling operation of the portable subscriber unit;
• and
• a power measurement element coupled to the receiver for measuring a plurality of powers received in the plurality of predetermined synchronized SQM slots,
• wherein the processing system is programmed for:
• calculating from said plurality of powers a value representing a total interference plus noise environment for the receiver;
• setting in response to calculating said value a threshold for signal power, wherein the threshold is set a predetermined amount above said value;
• thereafter receiving the message portion and determining therefrom a power of a signal indicative of said signal power;
• and
• choosing between accepting and rejecting the message portion in response to said power determined.